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| MANUAL OE ASTRONOMY,l 

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AND THE :,?- 

USE OF THE GLOBES, 

FOR, I \ 

SCHOOLS AND ACADEMIES, 



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ItENEY KIDDLE, 



PRINCIPAL OF P T 



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NEW YORK: 
NEWMAN & IYISON, 199 BROADWAY 

S. C. GRIGGS & CO., CHICAGO, ILL.; MOORE & ANDERSON, 

CINCINNATI ; A. M'FARREN. DETROIT ; 

J. C, IYISON & CO , ALBURN. 



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A 


MANUAL OF ASTRONOMY 




AND THE 


USE 


OF THE GLOBES, 




FOR 


SCHOOLS AND ACADEMIES. 




BY 




HENRY KIBBLE, 


PRINCIPAL 01 


1 PUBLIC SCHOOL NO, 2, CITY OF NSW YORK. 




NEW YOKkN— - 


N E W M A H .& rVISON, 


>-> 


199 BROADWAY. 


1852. 



a vS 



\%fT 



Entered according to Act of Congress, in the year 1852, 

BY NEWMAN & IVISON, 

In the Clerk's office of the Southern District of New York. 



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/» 



STEREOTYPED BY 

THOMAS B. SMITH, 
216 William St., N. Y. 



PREFACE. 



This little work, on the subject of Astronomy, has been prepared 
to supply a deficiency which the author has himself experienced, in 
teaching the elements of this interesting and useful science, and 
which has been a subject of complaint with many other teachers. 
The books that have hitherto appeared on the subject, though by 
no means few, have either been meagre in facts, or have represented 
them in a manner neither well-arranged, nor adapted to their pur- 
pose as class-manuals. Some have, indeed, been excellent treatises 
on the subject ; but, making no distinction between definitions, or 
facts, and the matter intended to explain them, could not be con- 
veniently used by either teacher or pupil. 

The work here offered to teachers, is designed to remedy both of 
the defects here mentioned. It professes to give a sufficient num- 
ber of facts for an elementary treatise, accompanied occasionally by 
diagrams and brief explanations, which will serve at least to give a 
hint to the teacher, and afford him the means of adding farther 
illustration. "Works much more profusely illustrated scarcely ever 
do more, while very often the pupil receives from the fanciful rep- 
resentations, contained in them, a very erroneous idea of the sub- 
ject, and the expense of the book is unnecessarily increased. 

The plan of dividing the subject of each chapter into short and 
distinct paragraphs, each the answer to a question inserted at the 
bottom of the page, is, as far as the author is aware, original in a 
school treatise, on this subject, and has, he thinks, several advan- 
tages over the method of giving question and answer together. In 
the first place, the questions must, very often, contain the most 
important part of what the pupil should commit; secondly, the 
pupil, by confining his attention almost wholly to the answer, learns 
the definition or fact imperfectly ; and thirdly, the insertion of the 



PREFACE. 



questions with the answer, increases unnecessarily the size and ex- 
pense of the work. 

The introduction of questions, where possible, which the pupil is 
to answer from his acquired knowledge of the subject, and not by 
rote, is a feature which the author has seen in no other work on 
the subject. 

Most of our Elementary Astronomies pay little or no attention 
to the use of the artificial globes. The schools are generally sup- 
plied with globes, which, for the want of a manual on the subject, 
serve only to adorn the school-room. The pupil is, by this means, 
deprived of one of the best means of illustrating the subject, as well 
as of much practical information, which the use of the globe would 
indelibly impress upon his mind. This deficiency the author has 
endeavored to supply, b}' the second part of the work, which may, 
without difficulty, be studied in connection with the first. This 
portion of the work has been made more extensive than is gener- 
ally found in elementary treatises, without comprehending what 
could only be expected in a treatise of a higher character. 

Another motive has also induced the preparation of this work. 
The author has seen, with regret, that many persons, at the present 
time, appear to regard this science as unimportant or unsuitable to 
our Common Schools. "Without entering into any argument to 
show the contrary, it will suffice to say, that a science whose pro- 
gress is the peculiar glory of modern times, — which, in an important 
manner, illustrates geography, — which is necessary to the navigator, 
— which teaches the true character and position of our own world, 
as well as the character of the universe, of which it forms a part, — 
and which imparts to the mind of the student, a true and sublime 
idea of the character and power of the Almighty Creator thereof, — 
can scarcely be less important than the science which teaches locali- 
ties on the earth, or associates with them the memory of the follies, 
the vices, and the wars of mankind. 

If this little book shall be found acceptable to teachers, as an 
auxiliary in imparting instruction in this truly sublime science, the 
author will esteem himself well rewarded for the labor of prepar- 
ing it. 



Ui.tttr-ftt*.; 

PAGE 

IXTRODrCTIOX TnE HlSTOEY OF AsTROXOMY, . . . 9 

PART I. 

CHAPTER 

I. Mathematical Defixitioxs, 15 

II. The Heayexly Bodies, 18 

III. Plaxetaey Motioxs, 23 

IV. The Doctrixe of the Sphere, .... 27 
V. The Sux, 41 

YI. The Inferior Plaxets, 44 

YII. The'Earth, . ' . . . . . . . 46 

YIII. The Atmosphere of the Earth, «. 48 

IX. The Moon, . . . ' 51 

X. Mars, * 54 

XL Jupiter, . 55 

XII. Saterx, 56 

XIII. Uranus or Hersciiel, 58 

XIY. ISTeptuxe or Leyeerier, . . . . . 58 

XY. The Asteegids, .59 

XVI. Apparext Motioxs of the Heayexly Bodies, . 60 

XYII. Eclipses, 68 

XYIII. Tides, 66 

XIX. Parallax, .69 

XX. Eefractiox axd Twilight, 71 

XXI. Time, . . . 73 



Vlll CONTENTS. 

CHAPTER PAGE 

XXII. Precession, etc., 78 

XXIII. Comets, 80 

XXIV. Fixed Stars, 82 

XXV. Constellations, 85 



PAKT II. 

the artificial globes. 

I. Appendages to the Globes, 92 

II. Problems for the Terrestrial Globe, . . . .93 
III. Problems for the Celestial Globe, . . . .110 

Table I. Statistics of the Solar System, . . . . 11-i 
" II. The Secondary Planets, 115 

Glossary of Astronomical Terms, 116 

Questions for Review, 122 



INTRODUCTION, 



HISTOKY OF ASTRONOMY. 

Astronomy is supposed to be the most ancient of 
sciences. The sublime spectacle of the starry heavens, 
would naturally, at a very early age, attract the atten- 
tion, and excite the admiration of the most careless or 
ignorant observer ; and the curiosity of mankind would 
be early aroused to ascertain the nature of those "reful- 
gent lamps" which lend so much splendor and beauty 
to the otherwise sombre gloom of night. Accordingly, 
it is stated that shepherds and herdsmen were the first 
who endeavored to explore the wonders of that mag- 
nificent scene which their occupation obliged them to 
survey, from year to year, while watching their flocks 
by night, under the open sky. The shepherds of Chaldea, 
and the priests of Egypt and India, had, in remote an- 
tiquity, made some progress in astronomical discovery. 
They had, it is said, calculated the length of the solar 
year with tolerable correctness, and could even predict, 
within a certain time, the occurrence of solar and lunar 
eclipses. From these countries, too, we are told, Py- 
thagoras, a Grecian philosopher, about 500 years before 
the Christian era, obtained a knowledge of the true 



INTRODUCTION". 



solar sy stem, which he published, at that time, in Greece 
and Italy. But though astronomy thus early engaged 
the attention of men, there is no science on which more 
false and absurd ideas were entertained, in ancient and 
even in modern times, up to comparatively a very re- 
cent date. Unacquainted with the true method of 
astronomical research, and destitute of instruments with 
which to make the necessary observations, the progress 
of the ancients towards a just conception of the nature 
of the heavenly bodies, and the true system of the uni- 
verse, was exceedingly slow. As they trusted to the 
fallacious evidence of their senses alone, they were often 
bewildered in a labyrinth of conjecture, and frequently 
entertained the most absurd and extravagant concep- 
tions to account for the phenomena presented to their 
view. The system of Pythagoras, being entirely at 
variance with these conceptions, was believed only by a 
very few ; while, by the majority of mankind, it was en- 
tirely rejected, and therefore soon fell into neglect and 
forgetfulness. 

Eespecting the shape of the earth, and the means by 
which it is sustained in space, even the learned men of 
antiquity entertained the most wild and extravagant 
ideas. While a very few vainly endeavored to prove 
its rotundity, it was generally supposed to be a vast 
circular plane, supported in an incomprehensible man- 
ner, according to some, by a huge serpent, tortoise, or 
elephant. Some fancifully ascribed to it the shape of a 
cylinder, others that of a canoe ; while the learned and 
accomplished Aristotle, a prodigy of genius, asserted j 
that its figure is that of a timbrel, — showing in what an 



HISTORY OF ASTRONOMY. 



abyss of folly, even the most talented men may plunge 
themselves, when they leave the true path of scientific 
research, the patient observation of facts, to indulge in 
vain and idle speculation. 

The first observations, of importance, were made at 
Alexandria, in Egypt, about 300 years before Christ, 
when the positions of several of the zodiacal stars were 
correctly defined. It was not, however, until 160 years 
later, that any further progress of importance was made. 
Hipparchus, the founder of Grecian astronomy, flour- 
ished at Ehodes, 140 years before Christ; and, as he 
discarded the idle and absurd notions generally enter- 
tained, and carefully observed and recorded the places 
and appearance of the heavenly bodies, he made many 
valuable discoveries, and became justly pre-eminent 
among ancient astronomers. 

He discovered the precession of the equinoxes, the 
eccentricity of the sun's apparent orbit, the parallax of 
the planets, and the time of the moon's sidereal and sy- 
nodical revolutions ; defined the length of the solar and 
tropical year, and determined the places of more than a 
thousand of the fixed stars. He, moreover, invented the 
artificial sphere, and divided the heavens into 49 con- 
stellations, placing 12 in the zodiac, 21 in the northern, 
and 16 in the southern hemisphere. He was also the 
first who employed latitude and longitude to define the 
position of places on the surface of the earth. 

About 250 years after Hipparchus, flourished the 
celebrated Ptolemy. He published several works, con- 
taining everything then known of the science of astron- 
omy, and, in one of them, explained a new and original 



INTRODUCTION. 



theory of the planetary motions, invented by himself, 
and called after him, the Ptolemaic system. 

It supposed the earth to be fixed immovably in the 
centre of the universe, while all the heavenly bodies 
revolve around it, in the following order: the Moon, 
Mercury, Yenus, the Sun, Mars, Jupiter, Saturn, and 
the stars. Each of these bodies, he supposed, was set in 
a hollow, crystalline sphere, perfectly transparent, by 
which it was carried around the earth, and prevented 
from falling upon it. This system, though so manifestly 
absurd and erroneous, was universally believed to be 
true until the sixteenth century. 

In the year 1543, Copernicus, a Prussian astronomer, 
and a man of a comprehensive and original genius, pub- 
lished a work on the motions of the celestial orbs, in 
which he revived the long- neglected system of Pythago- 
ras, confuting, by a variety of arguments, the false sup- 
position of all the bodies revolving around the earth ev- 
ery day, and boldly asserting the rotation of the earth on 
its axis. This w r ork was respected but by very few, while 
it was generally rejected, and contemned as chimerical 
and absurd. Its most distinguished opponent, however, 
was Tycho Brahe, an eminent Danish nobleman, who 
was born in 1546, and devoted the whole of his life to 
his favorite science, astronomy. He carried the use of 
instruments to a greater extent than any previous as- 
tronomer, and accumulated a vast store of facts and 
statistics relating to the heavenly bodies. Unfortunately, 
he was unable to agree with Copernicus, as to the true 
system of the world, and he therefore invented and pub- 
lished, in opposition to him, an original system, called 



HISTORY OF ASTRONOMY. 



after himself, the Tychonic system. In this system, the 
earth is placed in the centre of the universe, with the 
sun, moon, and stars revolving around it, while the plan- 
ets revolve around the sun, and are carried with it 
around the earth. It was adopted by scarcely any ex- 
cept the astronomer's own pupils. 

Galileo, in 1610, availing himself of the invention of 
the telescope, was enabled to make several important 
discoveries, by which the rotation of the earth on its 
axis was fully confirmed, and the hypothesis of Tycho 
Brahe exploded. Such, however, was the ignorance of 
the age, that it was deemed irreligious to believe in the 
doctrine of the earth's motion, and Galileo, in his seven- 
tieth year, was obliged publicly to acknowledge himself 
in error, and, contrary to his own convictions, deny the 
fact of its rotation. But the truth could not long be 
crushed. The great Kepler arose, and, profiting by the 
vast stores which the labors of Tycho Brahe had accu- 
mulated, after many years of patient and incessant study, 
he arrived at those brilliant discoveries, called " Kepler's 
laws." 

In the latter part of the seventeenth century, Sir Isaac 
Newton, by making known the law of universal gravi- 
tation, set the seal of confirmation upon the labors and 
teachings of the eminent men who had preceded him, 
and prepared the way for the brilliant discoveries of 
more modern times. Since that period, the science has 
rapidly and steadily progressed from year to year, filling 
men's minds with admiration and amazement at the 
sublime and startling facts which have been successively 
made known by its votaries. Among the many illus- 



INTRODUCTION. 



trious men who have devoted their lives to this pursuit, 
the names of Herschell and Le Yerrier deserve particular 
commemoration, as the discoverers of the two most dis- 
tant planets of the solar system. In addition to these 
two bodies, fifteen minor planets or asteroids have 
been discovered between Mars and Jupiter, during the 
present century, while astronomers, in addition to these 
achievements in our own system, have passed beyond, 
into the illimitable fields of space, and revealed many of 
the wonders of the starry universe. The achievements 
of astronomy are truly astonishing, and furnish the most 
striking illustration of what can be accomplished by the 
faculties of man, feeble as they are, when constantly and 
systematically directed upon the investigation of any 
subject. 



PAKT I. 



CHAPTEE I. 

MATHEMATICAL DEFINITIONS. 

An Angle is the inclination of two lines which, meet 
in a point. 

Angles are of three kinds ; right, obtuse, and acute. 

Fig. 1. 

A right angle is one formed by 
one line meeting another perpendicu- K ^^ 

larly, and contains 90 degrees. 






An obtuse angle is an angle great- 
er than a right angle, and contains 
more than 90 degrees. 

An acute angle is one less than a 
right angle, and contains less than 
90 degrees. 



Fig. 2. 




Fig. 4. 



Parallel lines are such as, being 
extended, will never meet. They Parallel Lines . 
may be either straight or curved. 



What is an angle? Of how many hinds are angles? What is a right an- 
gle ? What is an obtuse angle ? What is an acute angle ? What are parallel 
lines ? 



16 



ASTRONOMY. 



Fig. 5. 



A triangle is a figure bounded by 
three sides. 

A right-angled triangle is one 
which contains a right angle. 

An equilateral triangle is one 
which has equal sides. 



A circle is a figure bounded by a 
curve line, every part of which is 
equally distant from the centre. 

The circumference is the curve 
line that bounds it. 

The diameter is a straight line 
drawn through its centre from one 
point of the circumference to another. 

The radius is a straight line drawn from the centre to 
the circumference. 

An arc is any part of the circumference. 
A tangent is a line which touches the circumference 
in one point. 

The circumference of every circle is supposed to be 
divided into 360 degrees, each degree into 60 minutes, 
and each minute into 60 seconds. 

A semicircle is one half of a circle, and contains 180 
degrees. 




What is a triangle ? What is a right-angled triaugle ? What is an equilateral 
triansle ? What is a circle ? What is the circumference ? What is the diam- 
eter ? What is the radius ? What is an arc ? What is a tangent ? How is the 
circumference of every circle supposed to he divided ? What is a semicircle ? 



ASTRONOMY. 



17 




A quadrant is a quarter of a circle, and contains 90 
degrees. 

An ellipse is a curve line, from any point of which, if 
two straight lines be drawn to its foci, their sum will be 
always the same. 

Thus in the ellipse DBEG, F and F 
represent the foci, to which., if straight lines 
be drawn, whether from A, B, or C, the 
sum of each pair will be always the same. 

The longest diameter of an 
ellipse is called the major axis, 
and its shortest diameter the 
minor axis. 

Thus in the Figure, D E is the major 
axis, and B G the minor axis of the ellipse. 

A sphere or globe is a round body, every part of the 
surface of which is equally distant from a point within 
called the centre. 

A hemisphere is a half of a globe. 

The diameter of a sphere is a straight line drawn 
through the centre, terminated both ways by the surface 
of the sphere. 

The radius of a sphere is a straight line drawn from 
the centre to the surface. 

Circles drawn on the surface of a sphere are of two 
kinds, great and small. 

Great circles are those which divide the globe into 
two equal parts. 



What is a quadrant? What is an ellipse? "What are the longest and short- 
est axes called ? What is a sphere ? What is a hemisphere ? What is the 
diameter of a sphere ? What is the radius of a sphere ? Of how many kinds 
are circles, drawn on the sphere ? What are great circles ? 



18 ASTRONOMY. 



Small circles are those which divide the globe into 
two unequal parts. 

The poles of a great circle, are two opposite points on 
the surface of the sphere, equally distant from every part 
of its circumference. 

An oblate spheroid is a sphere flattened at the 
poles. 

The plane of a figure, is the imaginary even surface on 
which it may be supposed to be described. 

Circles drawn on the surface of a sphere, are parallel 
when their planes are parallel. 



CHAPTER II. 

THE HEAVENLY BODIES. 

Astronomy is the science which treats of the heav- 
enly bodies. 

The heavenly bodies consist of the Sun, Planets, Com- 
ets, and Stars. 

They may be divided into two general classes, Lumi- 
nous and Opaque bodies. 

Luminous bodies are those which shine by their own 
light 



What are small circles ? What are the poles of a great circle ? What is an 
oblate spheroid ? What is the plane of a figure ? When are circles of the 
sphere parallel ? 

What is astronomy? Of what do the heavenly bodies consist ? How may 
they be divided ? What are luminous bodies ? 



ASTEOXOM T. 19 



Opaque bodies are those which, shine only by light 
received from some luminous body. 

The sun and stars are luminous bodies. 

The planets and comets are opaque bodies. 

A system, in astronomy, is a certain assemblage of 
heavenly bodies. 

The Solar System is that which consists of the sun, 
with the planets and comets revolving around it. 

Planets are opaque bodies, which revolve around the 
sun. 

They are of two kinds, primary and secondary. 

Primary planets are those which revolve around the 
sun only. 

Secondary planets are those which revolve around 
their primaries, and, with them, around the sun. 

Secondary planets are sometimes called Satellites. 

There are eight primary planets in the solar system, 
viz., Mercury, Yenus, the Earth, Mars, Jupiter, Saturn, 
Herschell or Uranus, and Neptune or Leverrier, besides 
the minor planets or Asteroids. 

There are twenty-one secondary planets, viz., the 
Earth has one, Jupiter four, Saturn eight, Uranus six, 
and Neptune two. 

Mercury and Yenus are called inferior planets, because 
their orbits are within that of the earth. 

Mars, Jupiter, Saturn, Uranus, and Neptune, are called 



What are opaque bodies 1 What bodies are luminous ? What bodies are 
opaque ? What is a system ? What is the solar system 1 What are planets ? 
Of how many kinds are planets 1 What are primary planets ? What are 
secondary planets ? What are they sometimes called ? How many primary 
planets are there ? How many secondary ? Which are the inferior planets ? 
Which are the superior ? 



20 ASTEONOMY. 



superior planets, because their orbits are outside that of 
the earth. " 

The Asteroids are small planets which revolve around 
the sun, between the orbits of Mars and Jupiter. 

They are fifteen in number, viz., Yesta, Juno, Ceres, 
Pallas, Astraea, Iris, Hebe, Flora, Metis, Hygeia, Parthe- 
nope, Clio, Egeria, Irene, and Eunomia. 

Comets are bodies which revolve around the sun in 
very elongated orbits, and are generally accompanied by 
a long train of light. 

The Stars are those bodies which appear never to 
change their positions with respect to each other. 

They are, for this reason, called Fixed Stars. 

The Orbit of a planet, is the path in which it revolves 
around the sun or central body. 

The plane of the earth's orbit is called the Ecliptic. 

The Elongation of any body, is its angular distance 
from the sun. 

Fig. 9. Thus, if E represent the earth in its orbit, 

and V, or V, Venus in its orbit, the angle 
V E S, or V E S, will represent the elonga- 
tion of Venus at either of the two points. At 
I and O, it will be seen the elongation is noth- 
ing, while at V it is greatest. 

A body is said to be in Con- 
junction with the sun, when it 
appears in the same part of the 
heavens. 
Conjunction is of two kinds, Inferior and Superior. 




What are the asteroids 1 How many are there ? Name them. What are 
comets ? What are the stars ? What are they called ? What is the orbit of 
a planet? What is elongation ? When is a body said to be in conjunction ? 



ASTRONOMY. 



21 



Inferior conjunction is when the body is between the 
earth and the sun. 

Superior conjunction is when the body is on the op- 
posite side of the sun from the earth. 

A body is said to be in Opposition, when the sun and 
body are on opposite sides of the earth. 

A body is said to be in Quadrature with the sun, when 
it is 90 degrees distant from it. 

Thas V represents Venus in infe- Fig. 10. 

rior conjunction ; M, Mars in superior 
conjunction ; M', Mars in opposition ; 
and M", the same planet in quadra- 
ture. Its angular distance, or elonga- 
tion, S E M," being a right angle. 

The Disc of a body is 
the circular illuminated 
surface which it presents 
to our view. 

A Digit is the twelfth 
part of the diameter of 
the disc. 

The Axis of a body, is an imaginary line around which 
it revolves. 

Diurnal rotation is the revolution of a body on its 
axis, and is called its day. 

Annual revolution is the revolution of a body around 
the sun, and is called its year. 

The Mass of any body, is the quantity of matter which 
it contains. 




What is inferior conjunction ? What is superior conjunction ? What is op- 
position ? What is quadrature ? What is the disc of a body ? What is a 
digit ? What is the axis of a body ? "What is diurnal rotation ? What is an- 
nual revolution ? What is the mass of a body ? 



22 ASTRONOMY. 



The Density of any body, is the degree of compactness 
of its substance. 

The Angular diameter of a body, is its apparent diame- 
ter, expressed in minutes and seconds, as seen from the 
earth. 

The Linear diameter is its actual diameter. 

The heavenly bodies are, in general, oblate spheroids. 



QUESTIONS FOR EXERCISE. 

What is the elongation of a hody in quadrature ? 

What is the elongation of a body in inferior conjunction ? 

What is the elongation of a body in superior conjunction ? 

What is the elongation of a body in opposition ? 

What bodies can be in inferior conjunction ? 

What bodies can be in superior conjunction ? 

What bodies can be in opposition % 

What bodies can be in quadrature ? 

Can the elongation of Venus exceed 90 degrees 2 (Fig. 9.) 

Can that of Mercury ? 

Can that of Jupiter ? 

What is the greatest elongation of Mars ? — Saturn ? — Nep- 
tune? 

When Venus is in inferior conjunction, and Mars in opposition, 
what is tbe angular distance between the two bodies ? 

What is the angular distance of one from the other, if Venus 
is in inferior conjunction, and Mars in superior conjunction ? 

What is their angular distance, when Venus is in superior con- 
junction, and Mars in quadrature ? 



What is the density? What is the angular diameter? What is the linear 
diameter ? What is the shape of the heavenly bodies ? 



ASTRONOMY. 23 



CHAPTER III. 

PLANETARY MOTIONS. 

All the planets move in their orbits from west to east. 

A planet's revolution in its orbit, is sustained by the 
united action of two forces, viz., the Centripetal and Cen- 
trifugal forces. 

The Centripetal force is that which draws a body tow- 
ards the centre, or body around which it is revolving. 

It is also called the attraction of gravitation, being, in 
fact, the power which all bodies possess, of mutually 
attracting each other. 

The Centrifugal force is that by which a body tends 
to fly off from the orbit in which it is revolving. 

It increases with the velocity of the body. 

Laws, in astronomy, are general and invariable facts 
respecting the motions of the heavenly bodies. 

The following are the three great laws of planetary 
motion, discovered by Kepler, and hence called Kepler's 
laws : 

1. The planets' orbits are ellipses, having the sun or 
central body in one of the foci. 

2. The radius- vector of a planet's orbit, passes over 
equal spaces in equal times. 



In what direction do the planets move in their orbits ? How is a planet's 
revolution in its orbit sustained ? What is the centripetal force ? "What is this 
force also called 1 What is the centrifugal force ? How does it increase ? 
What are laws in astronomy ? Recite Kepler's laws. 



24 



ASTRONOMY. 



3. The squares of the periodic times, are in proportion 
to the cubes of the mean distances from the sun. 

The Radius- vector of a planet's orbit, is a line drawn 
from the central body to any point of the orbit. 

The Eccentricity of a planet's orbit, is the distance 
from the centre to either of the foci. 

The Aphelion is that point of a planet's orbit which is 
farthest from the sun. 

The Perihelion is that point of its orbit nearest to the 
sun. 

The point of the moon's orbit farthest from the earth 
is called the Apogee. 

The point nearest to the earth is called the Perigee. 

These two points are also called the Apsides. 

The line which joins them, is called the Apsis line, or 
line of Apsides. 

Let the annexed diagram rep- 
resent the orbit of a planet, S 
being the aun, in one of the foci, 
and O the centre of the orbit. 
Then the distance S O will rep- 
resent the eccentricity ; the point 
A the aphelion ; the point P the 
perihelion ; A and P the apsides ; 
and the line connecting them the 
apsis line. The lines B S, C S, 
D S, Ac. represent the radias-vec- 
tor in different positions, the spaces 
between them being supposed to 
be all equal to each other, and, according to the first law, passed over in equal 
times. The planet would, therefore, move over P G in the same time as A B, 
and thus its velocity is greatest at the perihelion, and least at the aphelion. 
The difference is not, however, in the case of any of the planets, so great as 




What is the radius-vector ? What is eccentricity ? What is the aphelion ? 
What is the perihelion ? What is the apogee ? What is the perigee ? What 
are these two points also called ? What is the apsis line ? 



ASTRONOMY. 25 



represented in the diagram. The difference of the earth's hourly angular velo- 
city, at the aphelion and perihelion, is only about four minutes, and its eccen- 
tricity, S O, only about 1-59 of its semi-axi&, A O, so nearly does its orbit resem- 
ble an exact circle. 

The velocity of a planet is increased or diminished, as 
it approaches or recedes from the sun. 

Of any two planets, that which is nearest to the sun 
moves with the greatest velocity. 

The planets' orbits are all inclined to the ecliptic, and 
cross it in two points. 

The Nodes are the two opposite points, where the orbit 
of a planet cuts the ecliptic. 

The Ascending Node is the point, at which the planet 
crosses the ecliptic from south to north. 

The Descending Node is the point, at which the planet 
crosses the ecliptic from north to south. 

The True place of a planet, is the place at which it is 
actually situated. 

The Mean place is that in which it would be, if it 
moved uniformly in a circle. 



When is a planet's velocity increased and diminished ? Which planet moves 
with the greatest velocity ? What is the position of the planets' orbits ? What 
are the nodes ? What is the ascending node? What is the descending node? 
What is the true place of a planet ? What is the mean place ? 



26 ASTEONOM Y. 


TABLE OF MAGNITUDES, DISTANCES, AND REVOLUTIONS 


OP THE PRIMARY PLANETS. 


Name. 


Diameter. 


Distance 
from the Sun. 


Annual 
Revolution. 


Diurnal 
Rotation. 




Miles. 


Miles. 


Yea-3. Days. 


Dj-3. Ilrs. 


Sun . . 


887,000 






25 10 


Mercury . 




3,200 


37,000,000 


88 


24 


Venus . . 




7,700 


68,000,000 


224 


23i 


Earth . . 




7,912 


95.000.000 


365* 


24 


Mars . . 




4.200 


142,000.000 


1 321 


24| 


Jupiter . . 




89,000 


485,000.000 


11 314 


10 


Saturn * < 




79,000 


890,000,000 


29 170 


10i 


Uranus 




35,000 


1,800,000,000 


84 5 


H 


Neptune . 




31,000 


2.850.000,000 


164 225 




TABLE OF ASTEROIDS. 


Name. 


Diameter. 


Distance from the Sun. 


Annual 
Revolution. 




Miles. 


Miles. 


Years. Days. 


Flora 




210.000,000 


3 98 


Vesta . 








270 


225,000,000 


3 230 


Iris * . 










227,000,000 


3 250 


Metis . 










227,000,000 


3 251 


Hebe . 










231,000,000 


3 285 


Astraea . 










245,000,000 


4 51 


Juno . , 








1,400 


254,000,000 


4 134 


Ceres 








1.600 


263,000,000 


4 222 


Pallas . 








2,100 


263,500.000 


4 226 


Hygeia . 










298,000.000 


5 199 


Parthenope 










234,000,000 


8 305 


Clio . . 










222,000,000 


3 206 


Egeria . 










245,000,000 


4 44 


Irene 










246,000,000 


4 54 


Eunomia 








252,000,000 


4 113 


What is the diameter of the sun ? What is the time of its diurnal rotation ? 


Mention the diameter of each of the primary planets ? State the distance of each 


from the sun ? What is the time of the annual revolution of each ? What is the 


time of the diurnal rotation of each 1 What is the diameter of each of the aste- 


roids as far as known? What the distance from the sun ? What the period of 


annual revolution ? 

- 



ASTRONOMY. 27 



CHAPTER IT. 

TEE DOCTRINE OF THE SPHERE. 
SECTION I. 

The artificial globes are two in number, viz., the Ter- 
restrial and Celestial globes, 

The Terrestrial globe represents the earth, with its 
natural and political divisions delineated on its surface. 

The Celestial globe represents the sphere of the heav- 
ens, in the centre of which the earth appears to be placed. 

The Constellations, together with the various circles 
used in astronomy, are laid down on its surface. 

A Constellation is a number of stars included within a 
certain space. 

The Axis of the earth, is an imaginary line around 
which it rotates. 

The Poles of the earth, are two imaginary points at 
the extremities of its axis, and are called the North, or 
Arctic pole, and the South, or Antarctic pole. 

The Celestial Poles are the extremities of the earth's 
axis extended to the heavens. 

The principal great circles drawn on the sphere, are 
the Equator, the Ecliptic, and the Meridians. 



How many and what are the artificial globes ? What does the terrestrial 
globe represent 1 What does the celestial 1 What are laid down on its sur- 
face ? What is a constellation 1 What is the axis of the earth ? What are the 
poles of the earth ? What are they called ? What are the celestial poles ? 
Mention the principal great circles. 



28 



ASTRONOMY, 



SECTION II. 

The Equator is a great circle whose plane divides the 
earth into northern and southern hemispheres. 

Latitude, on the earth, is distance north or south from 
the equator. 

It is reckoned on a meridian, from the equator to the 
poles. 

The greatest latitude of any place on the earth, is 90 
degrees. 

Parallels of latitude are small circles parallel to the 
equator. 

Their number is unlimited. 

The Tropics are two small circles parallel to the equa- 
tor, at the distance of 23i degrees from it. 

The Northern is called the tropic of Cancer, and the 
Southern the tropic of Capricorn. 

The Polar circles are two small circles parallel to the 
equator, at the distance of 23£ degrees from the poles. 

The Northern is called the Arctic 
circle, and the Southern the Antarctic 
circle. 

Meridians are great circles which 
pass through the poles at right angles 
with the equator. 

Longitude is distance east or west 
from any established meridian. 




What is the equator ? What is latitude on the earth ? How is it reckoned ? 
What is the greatest latitude of any place ? What are parallels of latitude ? 
How many are there ? What are the tropics ? What are they called ? What 
are the polar circles ? What are they called ? What are meridians ? What 
is longitude ? 



ASTRONOMY. 



29 




The first meridian is that from 
which longitude is reckoned. 

The meridian of London or Green- 
wich is generally employed as a first 
meridian. 

The greatest longitude of any place 
on the earth, is 180 degrees. 

SECTION III.— ZONES. 

Zones are those divisions of the earth's surface which 
are bounded by the tropics and polar circles. 

There are five zones, viz., 
one Torrid, two Temperate, and 
two Frigid zones. 

The Torrid zone is that which 
is included within the tropics, 
the equator passing through the 
middle of it. 

It is 47 degrees wide ; 23i 
degrees on each side of the 
equator. 

The North Temperate zone is 
that which is included within the tropic of Cancer, and 
the Arctic circle. It is 43 degrees wide. 

The South Temperate zone is that included within 
the tropic of Capricorn and the Antarctic circle. It is 
43 decrees wide* 




What is the first meridian 1 What meridian is generally used as such 1 
What is the greatest longitude of any place ? 

What are zones % How many, and what are they ? "What is the ton-id zone ? 
How wide is it ? What is the north temperate zone ? What is the south tem- 
perate zone ? What is the width of each 1 



30 



ASTROXOM Y. 




Fig. 15. The North Frigid zone is that 

contained within the Arctic circle, 
having the north pole for its centre. 
The South Frigid zone is that 
contained within the Antarctic cir- 
cle, having the south pole for its 
centre. 

The distance across each of the 
frigid zones, is 47 degrees, or 23 £ degrees each side of 
the pole. 

SECTION IV.— THE HORIZON. 

The Horizon of any place, is the circle which separates 
the visible part of the heavens from the invisible. 

There are two horizons, 
the Sensible and the Rational 
horizon. 

The Sensible horizon is 
that small circle on the 
earth which bounds our 
prospect, where the earth 
and sky appear to meet. 

The Rational horizon is a 
great circle which is parallel 
to the sensible horizon, and whose plane divides the 
earth into upper and lower hemispheres.* 



Fig. 16. 

ScixsiMe Z Hoi-izcm. 




What is the north frigid zone ? What is the south frigid ? How many de- 
grees across each of the frigid zones? 

What is the horizon ? How many horizons are there ? What is the sensible 
horizon ? What is the rational horizon ? 



lL 



ASTRONOMY. 



31 



The poles of the horizon, are called the Zenith, and the 
Nadir. 

The Zenith is that point which is exactly over our 
heads. 

The Nadir is the point opposite to the zenith, or di- 
rectly under our feet. 

The cardinal points of the horizon are the North, East, 
South, and West. 

Vertical circles are great circles which pass through 
the zenith and nadir, and cut the horizon at right 
angles. 

The Prime "Vertical is that vertical circle which passes 
through the east and west points of the horizon. 

The Meridian of a place corresponds to a vertical cir- 
cle which passes through the north and south points of 
the horizon. 

The Azimuth of a heav- 
enly bod}^, is its distance 
from the meridian, measured 
on the horizon. 

The Amplitude of a heav- 
enly body, is its distance 
from the prime vertical, 
measured on the horizon. 

Thus, in Figure 17, let NESW 
represent the plane of the horizon, N S 
the meridian, and W E the prime ver- 




23a&b? 



What are the poles of the horizon called ? What is the zenith 1 What is 
the nadir ? What are the cardinal points of the horizon ? What are vertical 
circles ? What is the prime vertical 1 What is the meridian of a place ? 
What is the azimuth of a heavenly body ? What is the amplitude of a heav- 
enly body 1 



32 



ASTRONOMY. 



tical: then, if A be the position of the sun at its rising, A E will represent its 
amplitude, and A N its azimuth. 

The Altitude of a body, is its distance above the hori- 
zon, reckoned on a vertical circle. 

The Zenith Distance of a body, is its distance from the 
zenith, reckoned on a vertical circle. 

The Polar Distance of a bod}', is its distance from the 
pole, reckoned on a meridian. 

Circles of daily motion, are those circles which the 
heavenly bodies describe in their apparent daily revolu- 
tion around the earth. 

The Diurnal Arch is that part of a circle of daily mo- 
tion which a heavenly body describes from its rising to 
its setting. 

The Nocturnal Arch is that part which it describes 
from its setting to its rising. 

The sphere, with respect to the circles of daily motion, 
has three positions, Eight, Oblique, and Parallel. 

A Eight Sphere is that in 
which the circles of daily mo- 
tion are perpendicular to the 
horizon. 

A Parallel Sphere is that in 

which the circles of daily 

motion are parallel to the 

horizon. 

j?acG An Oblique Sphere is that 



Fig. 18. 
Rigltt SpKexe 



genfth 



Pole 




Pole 



What is altitude? What is zenith distance? What i3 polar distance? 
What are circles of daily motion? What is the diurnal arch? What is the 
nocturnal arch ? How many positions has the sphere ? Wliat is a right sphere I 
What is a parallel sphere ? What is an oblique sphere ? 



ASTRONOMY. 



Fig. 19. 
Parallel Sphere 

""Polle"" 















[ "iioi- 


izon j 


EcfU 


acor 















Fig. 20. 
OMigue Sphere 

" A 



in which the circles of daily mo- 
tion are oblique to the horizon. 

Those who live under the equa- 
tor have a right sphere, those at 
the poles a parallel sphere, and 
those between the equator and the 
poles an oblique sphere. 

The circle of perpetual appari- 
tion, is that circle in which the 
stars never set. 

The circle of perpetual occupa- 
tion, is that in which the stars 
never rise. 

Thus, iu Fig. 20, A H repi'esents the circle of 
perpetual apparition, and B H the circle of per- 
petual occultation. P H represents the altitude 
of the pole, which always corresponds to the 
latitude of the place. Thus the latitude of New- 
York is 41 degrees north ; hence the altitude 
of the north pole hi that city, is 41 degrees, 

and the circle of perpetual apparition extends 41 degrees from the pole. The 
altitude of the equator or equinoctial, is always equal to the difference be- 
tween the latitude of the place and 90 degrees. Consequently, the altitude of 
the sun at noon is always equal to the altitude of the equator, plus its north 
declination or minus its south declination, in the northern hemisphere ; and plus 
its south or minus its north declination, in the southern hemisphere. These state- 
ments may be easily verified by an examination of the diagram. 




What inhabitants of the earth have each ? What is the circle of perpetual ap- 
parition ? What is the circle of perpetual occultation 1 

2* 



34 



ASTRONOMY. 



SECTION V.— THE ECLIPTIC AND ZODIAC. 

The Equator, when referred to the heavens, is called 
the Equinoctial. 

The Ecliptic is a great circle drawn on the globe, in 
the plane of the earth's orbit, which it represents. 

The Ecliptic intersects the Equinoctial at an angle of 
23i degrees. 

The Cardinal points of the ecliptic, are the Equinoctial 
and Solstitial points. 

The Equinoctial points are the two opposite points, at 
which the ecliptic and equinoctial intersect each other. 

The Solstitial points are those points of the ecliptic, 
farthest from the equinoctial, or where it touches the 
tropics. 

The Equinoctial Colure is 
the meridian which rjasses 
through the equinoctial 
points. 

The Solstitial Colure is 
the meridian which passes 
through the solstitial points. 

Thus, in Fig. 21, S and S' represent 
the solstitial points, and E one of the 
equinoctial points, the other being in the 
hemisphere not represented in the dia- 
gram. 

The Zodiac is a zone or belt 16 degrees wide, encom- 




What is the equinoctial ? What is the ecliptic ? At what angle does the 
ecliptic intersect the equinoctial ? What are the cardinal points of the ecliptic ? 
What are the equinoctial points? What are the solstitial points? What is 
the equinoctial colure ? What is the solstitial colure ? What is the zodiac? 



ASTRONOMY. 



35 



passing the globe, at the distance of eight degrees on 
each side of the ecliptic. 

The planets, except most of the Asteroids, move within 
the zodiac. 

The ecliptic and zodiac are divided into twelve equal 
parts, called Signs. Each sign contains 30 degrees. 

The course of the sun, in his apparent yearly revolu- 
tion around the earth, is indicated by these signs. 

The sun appears to move, from west to east, through 
each sign successively, — while the earth passes through 
the opposite sign. 

This apparent motion is caused by the real revolution 
of the earth, in its orbit, around the sun. 

The following are the names of the signs, and the day 
on which the sun enters each of them : 



Spring 
signs. 


f Aries 
< Taurus 


b' 


Twenty-first of March. 
Twentieth of April. 


' Gemini 


n 


Twenty-first of May. 




[ Cancer 


25 


Twenty-first of June. 


Summer 

signs. 


< Leo 


a 


Twenty-third of July. 




[ Virgo 


w 


Twenty-third of August. 


Autumnal 


[ Libra 


rO= 


Twenty -third of September. 


< Scorpio 


Tit 


Twenty-third of October. 




( Sagittarius 


t 


Twenty-third of November. 


AY inter 


( Capricornus 
■< Aquarius 


V? 


Twenty-second of December. 
Twentieth of January. 




( Pisces 


X 


Eighteenth of February. 



What bodies move within it ? How are the ecliptic and zodiac divided ? 
What is indicated by the signs 1 How does the sun appear to move ? What 
is this apparent motion caused by ? Mention the names of the signs, and the 
day on which the sun enters each. 



36 ASTRONOMY. 



The Equinoctial points are the first degree of the sign 
Aries, called the Vernal equinox, and the first degree 
of Libra, called the Autumnal equinox. 

The Solstitial points are the first degree of Cancer, 
called the Summer solstice, and the first degree of Capri- 
corn, called the Winter solstice. 

The sun passes the equinoctial points on the 21st of 
March, and the 23d of September. 

It passes the solstitial points on the 21st of June, and 
the 22d of December. 

The Latitude of a heavenly body, is its distance north 
or south from the ecliptic. 

This is called Celestial Latitude. 

Celestial Longitude is distance on the ecliptic, reck- 
oned from the first degree of Aries, eastward round the 
globe. 

The greatest longitude of a heavenly hody, is 360 
degrees.' 

The Declination of a heavenly body, is its distance 
north or south from the equinoctial. 

Declination corresponds to latitude on the earth. 

The Right Ascension of a heavenly body, is its dis- 
tance from the first degree of Aries, reckoned on the 
equinoctial eastward round the globe. 

The greatest right ascension of a heavenly body, is 
360 degrees. 



Where are the equinoctial points, and what are they called ? Where the 
solstitial, and how named ? When does the sun pass the equinoctial points 1 
When the solstitial? What is the latitude of a heavenly body ? What is this 
called? What is celestial longitude? What is the greatest longitude of a 
heavenly body ? What is declination ? To what does it correspond ? What 
is right ascension ? What is its greatest amount ? 



ASTRONOMY. 



37 



The sun is said to be vertical to a place, when it is 
directly over that place. 

SECTION VI.— DAY AND NIGHT, SEASONS., &c. 

The succession of day and night, is occasioned by the 
rotation of the earth on its axis. 

- Fig. 22. 




In Figure 22, it will be seen, that the axis of the earth, in tbe positions 
A, B, C, and D, points in the same direction ; and that at A and C, each pole is 
presented alternately to the sun ; while at B and D, the axis leans sidewise to 
it, and both polar circles are equally illuminated. The following statements will 
be understood, from an inspection of this diagram : 

When is the sun said to be vertical to a place ? 

By what is the succession of day and night occasioned ? 



38 ASTItONOM Y. 



The change of the seasons, is caused by the inclination 
of the earth's axis to the ecliptic, and its revolution 
around the sun. 

The change of the seasons is regular, because the 
earth's axis always points in the same direction. 

When the Sun enters Cancer, the north pole is pre- 
sented to the Sun ; and summer is produced in the 
Northern hemisphere, and winter in the Southern. 

When the Sun enters Capricorn, the south pole is pre- 
sented to it ; and winter is produced in the Northern 
hemisphere, and summer in the Southern. 

When the Sun enters Aries, the earth's axis leans side- 
wise to it ; and spring is produced in the North temper- 
ate zone, and autumn in the South. 

When the Sun enters Libra, the earth's axis leans 
sidewise to it ; and autumn is produced in the North 
temperate zone, and spring in the South. 

Summer is produced in either hemisphere, by the rays 
of the sun striking that part of the earth directly, so that 
they are collected on a smaller surface. 

Winter is produced by the sun's rays striking a por- 
tion of the earth obliquely, so that the same amount of 
light and heat are spread over a greater surface. 

This will be evident, from an inspection of Figure 23, in which it will be 
seen, that the same quantity of rays that covers the north polar circle, covers the 
south temperate zone, and half the torrid zone ; the rays in the north temperate 
zone being direct, in the other oblique. 



By what is the change of the seasons caused ? Why is this change regular? 
When the sun enters Cancer, what are the effects ? When the sun enters 
Capricorn, what effects are produced ? When the sun enters Aries, what are the 
effects ? When the sun enters Libra ? What produces summer ? What pro- 
duces winter ? 



ASTRONOMY. 



Fig. 23. 




When the Sun is in either of the Equinoxes, the days 
and nights are equal, in every part of the earth. 

When the Sun is in either of the Solstices, all places 
in the same hemisphere have their longest day, and 
those in the other their shortest day. 

Places situated at either of the Poles, have continual 
day, during the whole six months the sun is in the same 
hemisphere ; and continual night, during the six months 
it is in the other. 

All places in the Frigid zones, have their day longer, 
or shorter, in proportion to their distance from the pole. 

The Antoeci are those people who live under the 
same meridian, and in the same degree of latitude, on 
the opposite side of the equator. 

The Perioeci are those who live in the same latitude, 
but in opposite longitude. 

The Antipodes are those who live diametrically oppo- 
site to each other. 

Their latitude and longitude, seasons, and day and 
night, are contrary to each other. 



When the sun is in either of the equinoxes, what is the effect on the day and 
night ? What, when the sun is in either of the solstices ? What is said of 
places at either of the poles 1 How is the day, at places in the frigid zone, 
proportioned 1 What are the Antoeci ? What are the Perioeci ? What are 
the Antipodes 1 What is said of their latitude, etc. ? 



40 ASTRONOMY. 



QUESTIONS FOR EXERCISE. 

What is the latitude of the north pole ? 

What is the latitude of a place under the equator? 

New York is about 49 degrees from the north pole, what is its 
latitude ? 

How far is it from the south pole ? 

What is the latitude of a place under the tropic of Cancer ? 

What, under the Antarctic circle ? — What, under the tropic of 
Capricorn ? 

Which is the largest zone ? — Which, the two smallest ? 

At which is the heat greatest? — At which, the cold ? 

What is the greatest altitude of a heavenly body ? 

Where is the altitude greatest? — Where is it nothing? 

The zenith distance of a star is 15 degrees; what is its al- 
titude ? 

The altitude of a star is 40 degrees ; what is its zenith distance ? 

In what position of the sphere do the inhabitants of New York 
live ? 

How many degrees wide is the circle of perpetual apparition in 
the latitude of New York \ — At the north pole ? 

How many degrees wide is it at the equator \ 

The declination of a certain star is 60 degrees north ; does it 
ever set in New York } 

Does it set in latitude 60° N. ? — Does it rise in latitude 40° S. ? 

What is the greatest latitude of the sun ? — Of a primary 
planet ? — Of a star ? 

What is the greatest declination of the sun ? — Of a primary 
planet ? — Of a star ] 

At what two points is the declination of the sun greatest? — 
At what points is its declination nothing ? 

What is the Right Ascension of the sun in the first decree of 



ASTRONOMY. 41 



Cancer ? — What in the first degree of Capricorn ? — What in the 
first degree of Libra ? — What in the vernal equinox ? 

What is the longitude of the sun at each of these points ? 

Where is its longitude nothing ? 

When the sun is at either of the equinoctial points, what is its 
altitude, at noon, in New York ? 

What is its greatest altitude, in New York, during the year ? 
— What is its least ? 

The declination of a certain star is 30 degrees north ; what is 
its altitude when on the meridian in New York ? — Its zenith 
distance ? 

What must its declination have been to be seen in the zenith ? 

When is it longest day in New York ? — When in Washington ? 

When is it shortest day at New York ? — At Cape Horn ? 

When are the days and nights equal in New York ? — When 
in Boston ? — When at the equator ? 

A star is seen on the meridian, in New York, at an elevation 
of 40 degrees; what is its amplitude, azimuth, and zenith 
distance ? 



CHAPTER Y. 

THE SUN. 



The Sun is a luminous body placed in the centre of 
the Solar System. 

It dispenses light and heat to all its attendant bodies. 

The Sun's Apparent diameter is about half of a de- 
gree, (32 min.) 



What is the sun ? What does it dispense ? What is its apparent diameter ? 



42 ASTEONOMY. 



Its Linear diameter is 887,000 miles. 

The Sun has three revolutions ; one, on its axis, in 25 
days and a half; another, around the centre of gravity 
of the system j* and a third, around the centre of the 
universe. 

The density of the Sun is only one fourth that of the 
Earth, being but little heavier than water. 

The Disc of the Sun, on being examined with a tel- 
escope, exhibits certain dark spots, which are constantly 
varying in number, size, and appearance. 

Though most of them are very small, yet some have 
been seen, more than 50,000 miles in diameter. 

They are mostly confined to a zone extending thirty 
degrees, on each side of its equator. 

Astronomers suppose the Sun to be an opaque body, 
surrounded by an atmosphere of luminous matter. 

The spots are supposed to be openings in the luminous 
atmosphere, through which the dark body of the Sun 
becomes visible. 

The spots appear to move across the disc of the Sun 
from east to west, occupying about two weeks in their 
passage. 



What is its linear diameter ? How many revolutions has it ? What is its dens- 
ity? What does its disc exhibit? How large are the spots? To what part 
of the sun are they confined ? What do some astronomers suppose the sun 
to be ? What are the spots supposed to be ? How do the spots appear 
to move ? 



* The centre of gravity of any number of bodies, is that point around which they all 
balance each other. If we take a large body, and connect it by means of a rod with a 
small one, the centre of gravity of the two, will be that point of the rod, on which they 
can be equipoised or balanced. 



ASTRONOMY. 43 



This appearance affords a proof of the Sun's revolution 
on its axis from west to east.* 

Light passes from the Sun to the earth with a velocity 
of 192,000 miles in a second, and reaches the Earth in 
about eight minutes. 

Two theories have been advanced, respecting the na- 
ture of light : 

1. That it is composed of exceedingly small particles 
of matter. This was the opinion of Sir Isaac Newton. 

2. That it is occasioned by rapid vibrations in a very 
etherial fluid, pervading all space. 

Many modern opticians of great eminence maintain 
the latter theory. 

Light proceeds from the Sun, in straight lines, and in 
all directions. 

The axis of the Sun, is nearly perpendicular to the 
plane of the Ecliptic, making with it an angle of about 
82i degrees. 



What does this appearance prove ? What is the velocity of light ? How soon 
does it reach the earth ? Mention the two theories respecting the nature of 
light. How does it proceed from the sun ? What is the position of the sun's 
axis ? 



* It may appear singular, at the first view, to infer an eastward rotation of the sun 
from an apparent westward motion of the solar spots. But it must be remembered, 
that the sides of the sun and earlh presented to each other, at any time, are moving in 
opposite directions in space, though both bodies move in the same direction, in circu- 
lar motion. 



44 ASTRONOMY. 



CHAPTER VI. 

THE INFERIOR PLANETS. 

The Inferior Planets are Mercury and Venus. 

Mercury is the smallest of the eight primary planets, 
and the nearest to the Sun. 

Mercury is rarely visible to the naked eye, because it 
is so near the Sun. 

Its greatest Elongation is about 29 degrees. 

The Velocity of Mercury in its orbit is 110,000 miles 
an hour. 

The Inclination of Mercury's orbit, as well as its ec- 
centricity, is greater than that of any other of the eight 
primary planets. 

Its Density is also greater, being twice that of the Earth, 
or as heavy as lead. 

Venus is the second planet from the San. 

The Orbit of Venus is nearly a circle, and is very lit- 
tle inclined to the Ecliptic. 

The greatest Elongation of Venus is 47 degrees. 

Venus is called the Morning Star, when it is west of 
the Sun, and rises before it. 

It is called the Evening Star, when it is east of the 
Sun, and sets after it. 



Which are the inferior planets ? What is said of Mercury ? Why is it rarelv 
visihle ? What is its greatest elongation ? What is its velocity in its orbit ? 
What is said of the inclination of its orbit, and its eccentricity ? What of 
its density ? What is Venus ? What peculiarities in its orbit ? What is its 
greatest elongation ? When is it called the morning star ? When the evening 
star? 



ASTRONOMY, 45 



Ve n us is a Morning and an Evening Star alternately 
during 290 days. This is caused by the Earth's revolv- 
ing round the Sun the same way. 

The axis of Venus, makes an angle of 15 degrees with 
the plane of its orbit. 

The Tropics of Venus, therefore, are 75 degrees from 
her Equator, which makes her Torrid Zone and Polar 
Circles, 150 degrees wide. 

Fig. 24. 




This will be easily understood, on inspecting the annexed diagram, which 
represents the sun in her northern tropin when all places situated more than 
15 degrees north of her equator, have constant day, and all more than 15 degrees 
south of it, constant night. This produces winter at the equator, and within 
the south polar circle, and summer within the north polar circle. In one fourth 
of her year, when the sun will have arrived at the equator, there will be equal 
day and night all over the planet, summer at the equator, autumn within the 
north polar circle, and spring within the south polar circle. As the sun ai rives 
at the equator, and departs at its greatest distance from it, twice during the 
year, there must be two summers and winters, at that part of the planet, during 
a period of 224 days ; and a summer and winter at each of the poles, which suf- 
fer a change from the burning heat of a vertical sun and constant day, to the in- 
tense cold of perpetual night. 

The Phases of Mercury and Venus, when viewed 
through a telescope, appear similar to those of the Moon. 



How long is Venus a morning and evening star alternately ? How is this 
caused? What angle does its axis make with the plane of its orbit ? How far 
are her tropics from her equator? How wide is her torrid zone and polar. cir- 
cles ? What phases does Venus pi*esent 1 



46 ASTRONOMY. 



The Transit of Mercury or Venus, is its passage across 
the Sun's disc. 

A Transit takes place, when, at the time of inferior 
conjunction* the planet is at or near one of its nodes. 

At the time of a Transit, Mercury or Venus appears 
like a small black spot, passing across the disc of the 
Sun. 

This appearance affords a proof that they are opaque 
bodies, 

The transits of Venus afford a method for calculating 
the distance of the Earth from the Sun, 

The last transit took place in 1769 ; the next will occur 
in 1874. 



CHAPTER VIL 

THE EARTH. 

The Earth is the planet on which we live, and is the 
third from the Sun. 

Its shape is an oblate spheroid, or very nearly a 
sphere. 

Its Equatorial diameter, is about 7925 miles, and its 
Polar diameter is 26 miles less, 



What is the transit of Mercury or Venus ? When does a transit take place ? 
How do Mercury and Venus appear during a transit ? What does this prove ? 
Why are the transits of Venus important ? When did the last transit occur ? 
When will the next ? 

What is the earth ? What is its shape ? What are its equatorial and polar 
diameters ? 



ASTRONOMY. 47 



We have the following proofs that the Earth is a 
spherical body: 

1. Navigators have sailed around it. 

2. The top of a distant object at sea, is seen before 
any other part. 

3. It casts a circular shadow on the disc of the moon, 
in a lunar eclipse. 

The Earth is 96,000,00-0 miles from the Sun, in sum- 
mer, and 94,000,000 miles in winter; its mean distance 
is 95,000,000 miles. 

It is at its aphelion, July 1, and at its perihelion, 
January 1. 

The Earth revolves around the Sun, from west to 
east, once every year. 

It revolves on its axis, from west to east, once every 
24 hours, 

We have the following proofs that the Earth turns 
on its axis : 

1. All the heavenly bodies, appear to revolve around 
the Earth, from east to west, every day. 

2. The other primary planets are known to revolve 
on their axes. 

3. The trade winds and ocean currents, can be ac- 
counted for in no other way. 

The spheroidal shape of the Earthy is caused by its 
rotation on its axis.* 



How is the earth proved to be spherical ? How far is the earth from the 
sun ? When is it at its aphelion and perihelion ? In what time does it re- 
volve around the sun 1 In what time on its axis ? What proofs have we that the 
earth turns on its axis 1 What is the cause of the spheroidal shape of the earth 1 



* The velocity of the equatorial parts of the earth, is more than 2000 miles an hour. 



48 ASTRONOMY. 



The Earth moves in its orbit with a velocity of 68,000 
miles an hour. 

The Density of the Earth is o£ times that of water. 

The 
Moon. 



CHAPTER Till. 

THE ATMOSPHERE OF THE EARTH. 

The Earth is surrounded by an elastic, invisible fluid, 
called Air. 

The Earth's atmosphere consists of air, vapor, and 
many different gases. 

Its height is estimated to be about 45 miles. 

Air is composed of Oxygen and Nitrogen gases, in 
the proportion of 20 parts of Oxygen to 80 parts of 
Nitrogen. 

Oxygen supports life, heat, and vegetation. 

Air is 816 times lighter than water. 



What is the earth's velocity in its orbit ? What is its density ? By what is 
it attended ? 

By what is the earth surrounded ? Of what does its atmosphere consist 7 
What is its height? Of what is air composed? What is said of oxygen ? 
What is the weight of air ? 



This velocity diminishes, as Ave approach the poles, at which points it becomes noth* 
iug. The great velocity at the equator, occasions a much greater centrifugal force, at 
thut part than at any other ; in consequence of which, the water recedes from the 
poles, and accumulates at the equator, giving to the earth the shape mentioned in the 
text. 



ASTBONOM Y. 49 



The pressure of the atmosphere is about 15 pounds to 
every square inch. 

The Atmosphere becomes less and less dense, -as we 
ascend from the surface of the Earth. 

At the height of seven miles, it is only one fourth as 
dense as at the surface. 

Clouds are condensed vapors floating in the air, 

Wind is air put in motion. 

Motion is produced in the atmosphere, by any portion 
of it becoming heated, and hence made lighter, so that it 
rises ; and the heavier surrounding air, rushes in to fill 
its place. 

Winds differ in their Direction, Force, and Duration. 

The Trade Winds, are those which always blow in 
the same direction. 

Their direction is from the north-east on the north 
side of the Equator ; and from the south-east on the 
south side of the Equator. 

They prevail between the Equator, and SO degrees of 
north and south latitude. - 

Trade Winds are caused by the cold air rushing from 
the Poles to the Equator, together with the Earth's rota- 
tion on its axis. 

Land and Sea Breezes, are those which blow one part 
of the day from the land, and another part from the sea. 

They prevail in the islands of the Torrid zone. 



What is the pressure of the atmosphere ? When does the atmosphere be- 
come thinner ? What is its density at the height of seven miles ? What are 
•clouds? What is wind? How is motion caused, in the atmosphere? How 
do winds differ ? What are trade winds? What is their direction? Where 
do they prevail ? By what are they caused ? What are land and sea breezes ? 
Where do they prevail ? 



50 ASTRONOMY. 



Bain is occasioned by the clouds becoming condensed, 
and heavier than the air, so that they descend to the 
Earth. 

Snow consists of particles of frozen vapor, which, be- 
ing but a little heavier than the air, descend gently to 
the Earth, 

Hail is produced by a sudden freezing of the drops of 
rain, when blown into the cold regions of the atmos- 
phere. 

Fogs and Mists are clouds resting on the surface of 
the Earth, 

Fogs are caused by the warm vapors of the Earth's 
surface being condensed by the cold air above it. 

Dew is moisture deposited by the air, upon a cold 
surface. 

The following are some of the uses of the Earth's 
atmosphere • 

1. It scatters and equalizes the light of the sun. 

2. It supports life and vegetation, 

3. It waters the soil of different countries, by means 
of rain, etc. 

4. It affords a means of communicating sounds, 
Most of the other planets are supposed to have atmos- 
pheres. 



How is rain occasioned 7 What is snow? What is hail? What are fogs 
and mists ? By what are fogs caused ? What is dew ? Mention some of the 
uses of the atmosphere. Have the other planets atmospheres T 



A STB ON O MY. 51 



CHAPTER IX 

THE MOON. 

The Moon is a Satellite of the Earth, 

Its Diameter is about 2180 miles. 

Its Apparent diameter is about one half of a degree. 

Its Distance from the Earth is 240,000 miles. 

The Moon revolves around the Earth, from west to 
east^ in about 27^ days, (27 days, 7 h. 43 m.) 

The Moon revolves upon its axis in exactly the same 
time that it revolves around the Earth, 

The effect of this is, that the same hemisphere of the 
Moon is constantly turned towards the Earth. 

The time which elapses between one New Moon and 
another, is 29i days, 

This period is longer than a complete revolution, be- 
cause the Earth is revolving around the Sun the same 
way. 

The time from one New Moon to another, is called a 
Synodical month* 

The Moon's orbit is inclined to the ecliptic, at an angle 
of of degrees. 

The Axis of the Moon is nearly perpendicular to the 



What is the moon 1 What is its diameter ? What is its apparent diameter ? 
How far is it from the earth ? In what time does it revolve around the earth ? 
In what time does it revolve upon its axis ? What is the effect of this 1 What' 
time elapses between one new moon and another ? Why is this period longer 
than a complete revolution ? What is this period called ? At what angle is the 
moon's orbit inclined to the ecliptic ? What is the position of her axis, and 
what seasons has she 1 



52 ASTRONOMY. 



Ecliptic, consequently she experiences no change of sea- 
sons, except such as occur every month. 

The Moon generally rises, about 50 minutes later 
every successive day. 

The Moon rises later, because, as she advances east- 
ward in her orbit, the Earth has to turn on its axis so 
much farther to overtake her. 

Harvest Moon is the full moon 5 which occurs in Septem- 
ber and October, when it rises only a few minutes later, for 
several successive evenings; and, thus affording light for 
collecting the harvest, is therefore called Harvest Moon. 

Harvest Moon is caused by the Moon's orbit making 
a small angle with the Horizon, so that she descends 
but little below it, as she advances. 

The Moon is one half of the Earth's diameter, or 4000 
miles, nearer to us, when in the zenith, than when in 
the horizon. 

Phases of the Moon, are the different appearances 
which she exhibits to our view. 

New Moon occurs when she is in Conjunction, and 
the dark side is presented to us. 

First Quarter is when, after conjunction, she is in 
Quadrature, and half of her disc is visible to us. 

Full Moon is when she is in Opposition, and the 
whole of her disc is visible to us. 

Last Quarter is when, after Full Moon, she is again 
in Quadrature, and exhibits only half of her disc. 

Does the moon rise at the same hour every day ? Why does she rise later ? 
What is harvest moon ? By what is it caused ? Is the moon always at the 
same distance from us ? What are the moon's phases ? When does new moon 
occur? What is first quarter ? What is full moon ? What is last quarter ? 



ASTRONOMY. 



53 



When the Moon is between New Moon and Quadra- 
ture, and exhibits less than half of her disc, she is said 
to be Horned. 

When she is between Quadrature and Opposition, and 
exhibits more than half, but not the whole of her disc, 
she is said to be Gibbous. 

The phases of the Moon, are caused by different por- 
tions of her illuminated face, being turned towards the 
Earth. 

The Moon's disc, when viewed through a telescope, 
presents a diversified appearance of dusky and bright 
spots. 

The bright spots, are supposed to be mountains, and 
the dusky places, plains and valleys. 

Jig. 25. 




When is the moon said to he horned? When is she said to be gibbous? 
By what are the phases of the moon caused ? How does the moon's disc ap- 
pear, when viewed through a telescope ? What are the bright spots ? What 
the dusky spots ? 



54: ASTRO X03I Y. 



Some of the mountains Lave been calculated to be 
about five miles in height. 

The Moon is supposed to have very little, if any at- 
mosphere ; and, consequently, cannot be inhabited by 
beings like ourselves. 



CHAPTER X. 

M A R S. 

Mars is the fourth planet from the Sun, and is the 
smallest, except Mercury. 

It is about one seventh of the size of the Earth. 

The Axis of Mars is inclined towards its orbit about 
30 degrees. 

The Seasons, therefore, of Mars, resemble those of the 
Earth, but are nearly twice as long. 

The Oblateness of Mars' figure is more than twenty 
times as great as that of the Earth. 

Mars may be distinguished from the other planets, by 
its red, fiery color. 

The Disc of Mars, when viewed with a telescope, ex- 
hibits the outlines of apparent continents and seas ; the 



How high are the mountains in the moon ? Has the moon any atmosphere ? 
Is she inhabited ? 

What is Mars ? What is its size ? What is the inclination of its axis ? 
What seasons has it ? What is said of its figure ? How may it be distin- 
guished ? What does its disc exhibit when viewed with a telescope ? 



ASTRONOMY. 55 



continents appearing of a ruddy, and the seas of a green- 
ish color. 

The Disc of Mars also exhibits, brilliant white spots, 
alternately at each of the poles. 

These spots are supposed to be accumulations of ice 
and snow ; because they disappear at the pole as summer 
advances upon it. 

The ruddy color of Mars is supposed to arise from a 
very dense atmosphere which surrounds it. 

Mars is sometimes gibbous, but never horned; be 
cause it does not pass between us and the Sun. 



CHAPTER XL 

JUPITER. 



Jupiter is the largest planet in the Solar System. 

It is about 1B00 times as large as the Earth. 

The Axis of Jupiter, is nearly perpendicular to its 
orbit, and it has,, therefore, no change of seasons. 

The Orbit of Jupiter, makes an angle of about one 
degree with the plane of the Ecliptic. 

Jupiter is remarkable for the Oblateness of its figure, 
occasioned by its rapid rotation on its axis. 



What does its disc also exhibit ? What are these spots supposed to be ? 
Why ? What is the cause of the ruddy color of Mars ? What phases does it 
exhibit ? Why is it never horned ? 

What is Jupiter ? What is its size ? What is the position of its axis 1 
What seasons has it? What is the inclination of its orbit? For v/hat is Jupi- 
ter remarkable ? 



56 ASTRON01I Y. 



The Equatorial diameter of Jupiter is more than 6,000 
miles greater than its Polar diameter. 

The Velocity of the Equatorial parts of Jupiter is 
about 28,000 miles an hour, 

The Density of Jupiter, like that of the Sun, is only 
one fourth that of the Earth, being but little heavier 
than water. 

The Disc of Jupiter, when viewed with a telescope, 
exhibits dusky belts, parallel to each other, and at right 
angles with its axis. 

The Belts of Jupiter, are supposed to be the dark body 
of the planet, seen between clouds in its atmosphere. 

Jupiter is attended by four Satellites, all of which are 
larger than the Moon. 



CHAPTER XII. 

S A T U P. N. 

Saturn is the sixth planet from the Sun, and is the 
largest except Jupiter. 

It is 1,000 times as large as the Earth. 

The Axis of Saturn inclines 28 degrees towards the 
plane of its orbit. 



How much does its equatorial diameter exceed its polar ? What is the 
velocity of its equatorial parts ? What is its density ? What does its disc ex- 
hibit? What are the belts supposed to be ? By what is Jupiter attended ? 

What is Saturn ? What is its size ? What is the inclination of its axis ? 



ASTRONOMY. 57 



Its Seasons are, therefore, similar to those of the 
Earth, but about thirty times as long. 

The figure of Saturn is remarkable for being flattened 
at the Equator as well as at the Poles, and presents the 
appearance of an irregular square. 

The Density of Saturn is about one tenth as great as 
that of the Earth, being as light as cork. 

Saturn is encompassed by two large Eings of solid 
matter. 

These Eings are situated in the plane of its equator. 

The following are their dimensions : 

Breadth of inner ring, 17,000 miles. 

Interval between this and outer ring, 1,800 miles. 

Breadth of outer ring, 10,000 miles. 

Distance from the planet to the inner ring, 19,000 
miles. ' 

The thickness of the rings, is supposed to be 100 miles. 

They are proved to be opaque, by their casting a 
shadow on the planet, and receiving the shadow of the 
planet. 

They revolve on an axis, in the same time as the 
planet. 

The Disc of Saturn exhibits belts similar to those of 
Jupiter. 

Saturn is attended by eight Satellites. 



What seasons has it ? How is its figure remarkable ? What is its density ? 
By what is Saturn encompassed ? How are the rings situated ? Recite their 
dimensions '? What is the thickness of the rings 1 How are they known to be 
opaque ? In what time do they revolve ? What does the disc of Saturn ex- 
hibit? By how many satellites is Saturn attended ? 



3* 



58 .ASTRONOMY. 



CHAPTER XIII. 

URANUS OR HERSCHEL. 

Uranus is the seventh planet in the Solar System. 

It was discovered in 1781, by Sir William Herschel. 

Its magnitude is 85 times as great as that of the Earth. 

It revolves on its Axis in about 9i hours. 

It is supposed to be attended by six Satellites; but 
only three of these are positively known to exist. 

These Satellites revolve from east to west, — differing, 
in this respect, from all the other planets. 

To an inhabitant of Uranus, the Sun appears no 
larger than Venus does to us, — its apparent diameter 
being only one minute and a half. 



CHAPTER XIY. 

NEPTUNE OR LEVERRIER. 

Neptune is the most distant planet known in the 
Solar System. 

It was first observed, in 1816, by Dr. Gralle, of Berlin. 

The position of this planet was very nearly ascer- 
tained by Leverrier, a French mathematician, before its 



What is Uranus ? When, and by whom, was it discovered ? What is its mag- 
nitude ? In what time does it revolve on its axis ? By how many satellites is it 
attended ? How do they revolve ? How large does the sun appear at Uranus ? 

What is Neptune ? When, and by whom, was it discovered ? How and by 
whom was its position previously calculated ? 



•ASTRONOMY. 



actual discovery, by observing its action upon the planet 
Uranus. 

Keptune is believed to be accompanied by two Satel- 
lites, 

The light and heat of Neptune are 900 times less than 
at the Earth. 

This planet was discovered under circumstances, which give a greater tri- 
umph to modern science, than any other discovery recorded in the annals of 
human knowledge. During several years previous, Uranus had heen observed 
to deviate, in a mysterious manner, from the path assigned to it by the most 
careful calculations. Nothing but the supposition of another planet, existing 
somewhere in its vicinity, could account fc-r the disturbance. Accordingly, two 
mathematicians, Mr. Adaml^ of England, and M. Leverrier, of Paris, undertook 
to calculate the position of this unknown planet. Both, though unknown to 
each other, arrived at conclusions differing but slightly. M. Leverrier, how- 
ever, wrote to Dr. Galle, of Berlin, and requested him to direct his telescope to 
a certain point of the heavens. He did so, and the new planet was found within 
only one degree of the point specified by the mathematician, 



CHAPTER XT. 

THE ASTEROIDS. 

The Asteroids are a number of small bodies revolv- 
ing between the orbits of Mars and Jupiter. 

The Asteroids are distinguished from the other pri- 
marv planets, by the following circumstances : 

1. Their orbits have a much greater inclination to the 
ecliptic ; that of Pallas, making with it an angle of 34£ 
degrees. 



By how many satellites is it accompanied ? How much light and heat has it? 
What are the asteroids ? How are they distinguished from the other planets ? 



60 ASTROXO M Y. 



2. Their orbits are much more eccentric, especially 
those of Juno and Pallas. 

3. Their orbits, instead of being concentric, cross each 
other. 

4. They revolve around the San, at very nearly the 
same distance from it, and in about the same t'me. 

The magnitudes of these bodies have not been cer- 
tainly ascertained; but they are supposed to be all 
smaller than the Moon. 

Their average distance from the Sun, is about 260 mil- 
lions of miles. 

Their annual revolution is performed in about l£ 
years. 

All the Asteroids have been discovered during the 
present century. Ceres, Pallas, Juno, and Yesta, be- 
tween 1801 and 1807 ; and the others since 1815. 



CHAPTEE XVI. 

APPARENT MOTIONS OF THE HEAVENLY BODIES. 

All the heavenly bodies collectively, have two appa- 
rent revolutions around the earth ; an Annual revolution 
rom ivest to east, and a Daily revolution from east to iced. 

The first of these is caused by the Annual revolution 
of the Earth, and the second by its Diurnal rotation. 



What are their magnitudes ? What is their average distance from the son ? 
What is the time of their annua] revolution ] When were th<>y discovered ? 

What apparent revolutions have the heavenly bodies collectively ? How are 
these caused ? 



ASTRONOMY. 61 



The heavenly bodies rise in the east and set in the 
west, once every 24 hours, in consequence of the rota- 
tion of the earth on its axis. 

The planets individually have two apparent motions : 
viz., Direct and Retrograde. 

A planet's motion is said to be Direct, when it ap- 
pears to »move from west to east, according to the order 
of the Signs. 

A planet's motion is said to be Retrograde, when it 
appears to move backward, from east to west, or con- 
trary to the order of the Signs. 

When a planet appears to remain for some time, in 
the same point of the heavens, it is said to be Stationary. 

These appearances are caused by the real motion of 
the Earth, together with that of the planet. 

A planet appears to be Stationary, when it is moving 
directly towards, or from the Earth. 

In the annexed diagram, supposing the earth to be at rest at E, when Venus 
moves from V to V, she appears to move from D to B, westward or contrary 
to the oi'der of the signs ; and when she passes from V back again to V, she 
appears to move from B to D, or according to the order of the signs. But in- 
stead of being at rest, the earth is moving the same way. Suppose, therefore, 
she moves from E to E', while Venus is moving from V to V; when Venus 
arrives at V, she will have appeared to pass from D to B', in the same direc- 
tion as before, only not so far by the arc BB'. If the earth moves from E to E', 
while Venus is moving from V to V, Uranus will appear to pass from B to D', 
in the same direction as when the earth was at rest, only farther by the arc 
D D'. The earth's motion, therefore, does not affect the apparent direction of an 
inferior planet's motion, but makes it slower as it passes through its inferior, 
and quicker as it passes through its superior conjunction. The apparent motion 



Why do the heavenly bodies rise and set ? What apparent motions have the 
planets individually ? When is a planet's motion said to be direct ? When is 
it said to be retrograde 1 When is a planet said to be stationary ? By what 
are these appearances caused ? When does a planet appear to be stationary ? 



62 



ASTEONOM Y. 



of an inferior planet is therefore retrograde, while passing through its inferior, 
and direct while passing through its superior conjunction. Were the earth at 
rest, the planet would appear stationary at the points of greatest elongation, 
viz.. at V and V' ; but, owing to the earth's motion, this happens at a point 
between inferior conjunction and greatest elongation. 

The apparent motions of a superior planet, are somewhat different from those 
of an inferior planet, because the earth is moving faster than the planet ; but 
they may be explained in a similar manner. In passing through its superior 
conjunction, the motion of a superior pdanet is direct, because the combined 
effect of the earth's and planet's own motions, is to give it such a motion ; but in 
opposition, the earth moving more rapidly, passes the planet, and gives it an 
apparent retrograde motion. Thus, when Mars is moving from M to M', were 
the earth at rest, at E, it would appear to move from B to A, while the effect 
of the earth's motion is only to give it a greater apparent motion in the same 
direction. From Q. to &'. it is direct or retrograde, according as the effect of the 
earth's motion is greater or less than that of the planet. When these effects are 
the same, the planet appears stationary, which happens between quadrature 
and opposition. 

Fig. 26. 



<p' 
East \ 




"West 



ASTRONOMY. 63 



CHAPTER XVII. 

ECLIPSES. 

An Eclipse is the concealment of a heavenly body, 
by some opaque body, intercepting the Sun's rays. 

The principal Eclipses, are the Solar and Lunar. 

A Solar Eclipse, is an eclipse of the Sun. 

It is caused by the Moon's passing between the Earth 
and the Sun, and concealing the Sun from our view. 

A Lunar Eclipse, is an eclipse of the Moon. 

It is caused by the Moon's passing through the Earth's 
shadow. 

A Solar Eclipse can happen only at New Moon ; a 
Lunar Eclipse, at Full Moon. 

Eclipses are of two kinds, Total and Partial. 

A Total Eclipse is one, in which the disc is entirely 
concealed. 

A Partial Eclipse is one, in which only a part of the 
disc is concealed. 

An Annular Eclipse is an eclipse of the Sun, in which 
a bright ring appears around the dark body of the 
Moon. 

It happens when the Moon is too far from the Earth, 
to conceal the whole of the Sun's disc. 



What is an eclipse ? "What are the principal eclipses ? What is a solar 
eclipse ? How is it caused ? What is a lunar eclipse ? How is it caused ? 
When can these eclipses happen? Of how many kinds are eclipses? What 
is a total eclipse ? What is a partial eclipse ? What is an annular eclipse ? 
When does it happen 1 



64 ASTRONOMY. 



An eclipse does not happen at every new and full 
Moon ; because the Moon is not at, or near its node. 

The Ecliptic Limit, is the distance from the node, 
within which an eclipse can occur. 

The Solar Ecliptic Limit, extends 17 degrees, each 
side of the node. 

The Lunar Ecliptic Limit, extends 12 degrees, each 
side of the node. 

The Penumbra, is the faint shadow caused by a partial 
interception of the Sun's rays. 

The Earth's shadow, varies in length, as the distance 
of the Earth from the Sun. 

At the Earth's mean distance from the Sun, it is 
860,000 miles in length. 

Its breadth, where it eclipses the Moon, is about three 
times the Moon's diameter. 

The shadow of the Moon, when at its mean distance 
from the Sun and Earth, nearly reaches the surface of 
the Earth; and never exceeds 170 miles in diameter, 
where it intersects the Earth. 

The greatest number of eclipses that can happen in a 
year, is seven ; live of the Sun, and two of the Moon. 

The least number is two y which must both be of the Sun. 

Lunar eclipses are more frequent, at any particular 
place, than those of the Sun : 



Why does not aii eclipse happen at every new and full moon ? What is the 
ecliptic limit ? How many degrees does the solar ecliptic limit extend ? How 
many does the lunar ecliptic limit ? What is the penumbra ? What is the 
length of the earth's shadow ? What is its breadth, where it eclipses the 
moon ? What is the length of the moon's shadow ? What is its diameter, 
where it intersects the earth ? What is the greatest number of eclipses, that 
can happen in a year ? What is the leant number \ 



ASTRONOMY. 



65 



Because they are visible to an entire hemisphere ; while 
those of the San, are visible only to that part covered by 
the Moon's shadow. 

Eclipses sometimes take place, of Jupiter's Satellites. 

Occultation is the concealment of a planet or star, by 
the interposition of the Moon. 

In the annexed diagram, M represents the position of the Moon at the time 
of a total eciipse of the Sun ; and m its position at the time of a total eclipse of 
the Moon ; p and p, represent the Penumbra of the Moon ; and P and P, that of 
the earth. 

Fig. 27. 




Figure 28 represents an annular eclipse of the Sun ; in which, it will be per- 
ceived, the shadow of the Moon does not reach the surface of the Earth. 

Fig. 28. 




Why are lunar eclipses move frequent at any particular place ? What other 
eclipses sometimes take place ? What is occultation 1 



ASTEOXOM Y. 



CHAPTER XVIII. 

TIDES. 

Tides are the alternate rising and falling of the water, 
in Oceans, Eivers, etc. 

They are divided into Flood and Ebb, and Spring and 
Xeap Tides. 

Flood Tide is the rising of the water. 

When it is at its highest point, it is called High Water. 

Ebb Tide is the falling of the water. 

Flood and Ebb Tide happen twice every 25 hours. 

Spring Tide is the greatest flood and ebb tide. 

Neap Tide is the least flood and ebb tide. 

Tides are occasioned by the attraction of the Sun and 
Moon, acting unequally upon opposite sides of the Earth. 

The disturbing influence of the Moon, is three times 
as great as that of the Sun ; because it is so much nearer 
the Earth. 

The attraction of the Sun and Moon always produces 
similar tides, on opposite sides of the Earth, at the same 
time. 

Spring Tide is caused by the Sun and Moon's being 
on the same or opposite sides of the Earth, and thus 
acting together. 



What are tides? How are they divided? What is flood tide? At its 
highest point, what is it called ? "What is ebb tide ? How often do flood and 
ebb tides happen ? What is spring tide ? What is neap tide ? By what are 
tides caused ! How much greater is the disturbing influence of the moon ? 
Why ? Where are Bimilar tides produced ? By what is spring tide caused ? 



ASTB0X01IY. 67 



It occurs at New and Full Moon, or a short time 
afterwards. 

Neap Tide is caused, when the Sun and Moon are in 
quadrature, by their attracting forces counteracting each 
other. 

It occurs twice in each lunar month, when the Moon 
is in her first and last quarters. 

Primitive Tides, are those which are directly occa- 
sioned by the Sun and Moon ; such as those which take 
place in the ocean. 

Derivative Tides, are those which take place in nar- 
row bays, inlets, etc., owing to the primitive tides. 

The highest tides, occur in narrow bays, and arms of 
the sea, running up into the land. 

Lakes have no perceptible tides. 

The highest tides in the world, take place in the Bay 
of Fundy, where they rise about 70 feet. 

The average height, for the whole globe, is 21 feet. 

The tide rises about 50 minutes later, each successive 
day. 

This is caused by the Moon's advance in its orbit, so 
that the same place on the Earth's surface, does not 
come again under the Moon, until 50 minutes later. 

The tide does not rise, until several hours after the 
Moon has passed the meridian. 



When does it occur 1 When is neap tide produced, and by what ? How 
often does it occur ? What are primitive tides ? What are derivative tides 1 
Where do the highest tides occur ? Have lakes any tides ? Where do the 
highest tides in the world occur ? How high do they rise at that place 1 What 
is the average height for the whole globe? Does the tide rise at the same 
hour every day ? Why does it rise later ? Does the tide rise, when the moon 
is on the meridian 1 



ASTRONOMY. 



This is caused by the rotation of the Earth on its axis, 
and bj the inertia of the water. 

By inertia is meant, the resistance which all matter makes to be set in mo- 
tion, when at rest, or to he stopped, when in motion. In consequence of this 
property of matter, the waters do not immediately yield to the action of the 
sun and moon. The tide is also retarded by the friction of the waters on the 
bottom of the ocean. 

In the open sea, where the tide is least obstructed, it 
is about two or three hours behind the Moon. In New 
York, about 8£ hours. 

In the northern hemisphere, the highest tides occur, 
during the day in summer, and during the night in 
winter. 

Fig. 29. 

C 




Figure 29, represents Spring Tide during summer, in the northern hemi- 
sphere. The greatest elevation of the water, takes place at A and B, and the 
greatest ebb tide, at C and D, 90 degrees distant from those points. The Sun, 
attracting the water at A, more than any other part of the earth, and that at B, 
less than any other part, diminishes the gravity of the earth, at those two 
points ; in consequence of this, the centrifugal force, gives the water there a 
tendency to fly off from the earth ; and it rises at both places at the same time. 
The Moon being in a line with the Sun, whether in opposition or conjunction, 
raises a tide at the same points ; so that both their forces 'are united, and a high 
tide is the result. A comparison of the height of the water, at a and b, will 
explain, why the tide is highest, in the northern hemisphere, daring the day, 
and lowest during the night. 



What is this caused by ? How much behind the moon is the tide in the 
open sea ? How much in New York ? When do the highest tides occur in 
the northern hemisphere ? 



ASTRO N O M Y. 



Tig. 30. 




S %- 



Fig-are 30, represents Neap Tide. The effect of the Moon at C and D, and the 
Sun at A and B, is to equalize the water all over the globe, and cause the least 
flood and the least ebb tides. In conjunction and opposition, as in Figure 29, 
the tide raised by the Sun and Moon, is equal to the sum of their separate tides. 
in quadrature, — as in Figure 30, the tide raised is equal to the difference of 
their separate tidesi 

The pupil must remember, in inspecting these diagrams, that the effects of 
the Sun and Moon, are not, hy any means, so great as represented. The pro- 
tuberances are exaggerated, for the purpose of illustration ; but, in fact, they 
are only between two and three feet in 8000 miles ; so small as to make no 
perceptible change in the figure of the earth. 



CHAPTER XIX. 

PARALLAX. 



Parallax is the change of place which a body ap- 
pears to undergo, when viewed from different points. 

The Apparent Place of a heavenly body, is that in 
which it seems to be, when viewed from the Earth's 
surface. 



What is parallax ? What is the apparent place of a heavenly body ? 



70 



ASTRONOMY. 



The True Place, is that in which it would seem to be, 
if viewed from the centre of the Earth* 

The Diurnal Parallax of a body, is the difference be ; 
tween its true and apparent place. 

Horizontal ParallaXj is the diurnal parallax of a body 
when in the horizon. 

The Horizontal Parallax of the Sun, is about eight 
seconds. 

Diurnal Parallax is greatest at the horizon, and dimin- 
ishes towards the zenith, where it is nothing, 

The effect of Parallax, is to diminish the altitude of a 
body. 



Fig. 31. 



In Figure 31, let Z H represent a 
portion of the sphere of the heavens ; 
M, M 1 , etc., the moon at different alti- 
tudes ; and E the earth. To a specta- 
tor at A, when the moon is at M 3 , or in 
the horizon, it appears at hj but if 
viewed from E, it Would appear at H ; 
h is therefore its apparent, and H its 
true place ; and the difference H h is 
the diurnal parallax. As the body is in 
the horizon, it is also the horizontal par- 
allax. P p and O o, represent each the 
diurnal parallax, for its respective alti- 
tude. At M, the body being in the 
zenith, is in a line with the spectator, 
and centre of the earth; consequently 
there is no parallax, at that point. In the horizon, the parallax, is evidently the 
greatest. H h, is called the parallactic arc< and the angle H M a h, the angle of 
parallax. The same terms are applied to P p and o, and their corresponding 
angles. That parallax diminishes the altitude of a body, will be evident, from 
an inspection of the diagram. 




What is the true place ? What is diurnal parallax ? What is horizontal 
parallax ? How great is the horizontal parallax of the sun ? "Where is the 
diurnal parallax greatest ? Where is it nothing ? What ia the effect of 
parallax 7 



ASTRONOMY. 71 



Annual Parallax is the apparent change of place of a 
Stai-j when viewed from opposite points of the Earth's 
orbit* 

Only a very few of the Stars, have any annual paral- 
lax, on account of their immense distance from the 
Earth. 

The parallax of the nearest, is less than one second. 



CHAPTER XX, 

REFRACTION AND TWILIGHT, 

Refraction, in astronomy, is the change of direction 
which the rays of light undergo, in passing through the 
Earth's atmosphere, 

The Earth's atmosphere is net of a uniform density, 
but becomes less and less dense as we proceed from the 
surface. 

The rays of light are refracted, only when they strike 
the atmosphere obliquely. 

Refraction is therefore greatest, when the body is in 
the horizon, and nothing, when it is in the zenith. 

The effect of Refraction, is to increase the altitude of a 
body, or elevate it above the horizon. 



What is annual parallax ? How many stars have any ? How great is the 
parallax of the nearest 7 

What is infraction 7 Is the earth''s atmosphere of uniform density 7 "When 
are the rays of light refracted 7 "When is refraction greatest 7 When is it 
nothing 7 What is the effect of refraction 7 



72 



ASTRONOMY. 




ABC 



At the horizon it amounts to about 33 minutes. 

In consequence of Eefraetionj therefore, the Sun ap- 
pears above the horizon, when it is actually below it ; 
and the day is lengthened from six to ten minutes. 

ITi"". 32. * n ^ ie annexed diagram, let 

E represent the earth, and 
A B C D, portions or strata 
ef its atniosphere. of different 
densities, P the place of obser- 
vation, and H' P H, its horizon. 
Suppose a ray of light from 
the star S, strikes the atmos- 
phere at a ; on account of its 
density, instead of proceeding 
in a straight line, in the direc- 
tion S A, it describes a b, be 
and c P, and reaches the spec- 
tator at P. Now because we 
always see an object, in the 
direction, in which the ray of 
light strikes the eye, the star will be seen at S' instead of S. The difference is 
the refraction. As the atmosphere does not consist of distinct strata, as repre- 
sented, but diminishes uniformly in density from the surface of the earth, the 
broken line ab c P is in reality a Curve, and the line S'Pa tangent to it, at the 
point P, 

Twilight is that faint light, seen before the rising, and 
after the setting of the Sun. 

It is caused by the atmosphere's reflecting the light 
of the Sun. 

Twilight commences and ends, when the Sun is 18 
degrees below the horizon. 

Twilight is shortest at the Equator, and longest at the 
Poles. 

How great is it at the horizon ? What is the effect of refraction on the sun 
when rising and setting? What on the length of the day ? What is twilight? 
By what is it caused ■. When does twilight commence and end > Where is 
it shortest, and where longest ? 



ASTRONOMY. 



73 



£ig. 3$. 




Let A B C represent three places on the Sarth, aEd A K"> B H', C H, their 
horizons respectively. Let S represent the San, a little hefow the horizon, 
Whose rays pass through the atmosphere, in the direction S H*'. It will be seen 
that the sun is below the horizon of each place ; bet at C, there is twilight, be- 
cause the portion of tire atmosphere, K"C H, is illuminated^ and by it the light 
reflected on the place below ; at B, a smaller portion, H" g H, receives the 
rays cf the e&b ? while at A, the light entirely disappears. 



CHAPTER XXL 

TIME. 

Time is duration, as measured by the motions of the 
heavenly bodies. 

The Apparent motions of the Sun and Moon, afford 
standards for measuring time, 

A Day is either Solar, Sidereal, or Civil. 

A Solar day, is the period which elapses between the 
Sun's leaving the meridian of any place, until it arrives 
at it agaim 

The Solar days, are of unequal length. 



What is time 1 What afford standards for measuring it ? How many kinds 
of days are there ? What is a solar day 1 Are the solar days equal ? 



74 ASTRO XOM T- 



A Sidereal day, is the time which elapses between a 
star's leaving the meridian of any place, until it returns 
to it again. 

The Solar day, is about four minutes longer than the 
sidereal day. 

This difference is caused by the Earth f s motion east- 
ward in its orbit. 

Apparent time, is that reckoned by the apparent 
revolutions of the Sun. 

Mean time, is that reckoned by the average length of 
the solar days throughout the year. 

Clocks are constructed, to show Mean time. 

The Equation of Time, is the difference between Mean 
and Apparent time ; or the difference between time, as 
shown by the Sun, and that shown by a well<regulated 
clock. 

The Equation of Time, is greatest about the 8d of 
November, when it is about 16i minutes, and is to be 
subtracted. 

That is to say, when it is noon by the arm, it wants lft| minutes of it, by a 
well-regulated eloek. 

It is nothing, four times during the year^ namely, 
April loth, June 15th, September 1st, and Decem- 
ber 22d. 

The Equation of Time, is caused by the obliquity of 
the Ecliptic, and the variable motion of the Earth, in its 
orbit. 



What is a sidereal day ? How much longer is the solar than the sidereal 
day? What is the cause of the difference F What is apparent time ? What 
is mean time ? Which do clocks show ? What is the equation of time ? 
When is the equation of time greatest ? How great i3 it at that time ? When 
is it nothing? By what is it caused ? 



ASTRONOMY. 



75 




In Figure 34, let E represent the 
Earth, ABCPQ.R the Sun's appa- 
rent orbit; A being the aphelion, and P 
the perihelion. Were the Sun at rest 
at A. the place H, on the surface of the 
Earth, would, as it rotates on its axis, 
return to the Sun in exactly the time 
of one rotatidn, and the solar day would 
be no longer than the sidereal day ; but, 
daring one rotation, suppose the Sun to 
move, apparently, from A to B ; then 
the Earth will have to move more than 
one rotation, by the arc H h, in order to 
overtake the Sun. This causes the 
solar day to exceed the sidereal day, by 
an average difference of four minutes. 
But, as the San is not uniform in his 
motions, this is not always the differ- 
ence. To show this- draw a circle) am no, etc., and let each of the equal arcs, 
ant; mn, no-, l'epresent a space which the Sun would move over, during one 
rotation of the Earth, if he moved uniformly in a circle, and kept time with the 
clock. As at A, the Sun's motion is the most rapid, the divisions, as marked by 
the Sun, will be greater than those marked by the clock ; and the place H, will 
arrive at m, before it reaches the San at B, by the arc m b ; this is the equation 
of time : and, therefore, ichile the Sun moves faster than the clock, it will be noon 
by the clock before it is so by the Sun ; that is, the time shown by the Sun, will 
be slower than that shown by the clock, and the equation of time must be add- 
ed. This, it will be seen, is the case from A to P. From P to A, the reverse 
is the case ; the Sun moves slower than the clock, and the equation is to be sub- 
tracted. This fact may be expressed briefly, by saying, that the equation of 
time must be added, as the San moves from aphelion to perihelion, and sub- 
tracted, as it moves from 
perihelion to aphelion ; 
while at both those 
points, it vanishes. 

These, it must be re- 
membered, are the ef- 
fects of only one of the 
causes which produce 
the equation of time, viz. 
the unequal motion of 
the earth in its orbit. 
The other cause may be 
illustrated as follows : 




76 ASTRONOMY. 



Let the figure API represent the Northern Hemisphere ; A E I the Equinoc- 
tial ; and Ael the Ecliptic. Let the ecliptic be divided into equal portions, at 
the points bed, etc., and the equinoctial at ikl, etc. Draw meridians through 
bed, etc., cutting the equinoctial in B C D, etc* A h, be*, cdx etc., will then rep- 
resent arcs of longitude, and A B, B-C, C D, etc ; , arcs of right ascension) passed 
over by the San in equal periods of time, say from day to day* 

An inspection of the diagram, will show that these arcs do not correspond ; 
but that, while the arcs of the ecliptic are equal to each other, those of the equi- 
noctial are unequal, being shortest at the equinoctial points, A and I, and longest 
at the solstitial colure E. where the two circles are nearly parallel, and the 
divisions coincide. But differences of apparent time, are reckoned on the equi- 
noctial, and are therefore unequal; being represented by the unequal arcs A B, 
B C, C D, etc., whereas the equal divisions Ai, ik, kl, etc.; represent divisions 
of mean time, as shown by the clock, and thus the difference between these is 
the equation of time. Thus, when the Sun passes from A to b, the earth has 
only to move over A B, to overtake him, whereas, if he kept time with the 
clock, it would have to move over A i, a greater distance by B ?'. The Sun, 
therefore, comes to the meridian before it is noon by the clock, and is therefore 
faster — so that the equation must be subtracted. This is the case from A to e, 
but from e to I, the Sun is slower than the clock, and the equation is to be add- 
ed. In the third quarter of the ecliptic, it is again to be subtracted, and in the 
fourth, added* This is expressed, by saying, that the Sun is faster than the clock, 
from Aries to Cancer, slower from Cancer to Libra, faster from Libra to Capricorn, 
and slower from Capricorn to Aries ; while they agree at all those four points. 

The equation of time, being the result of both these causes acting together, 
is greatest culy when their effects are similar, and nothing only when they 
balance each other. This takes place at the times stated in the text. The 
following shews the appropriate sign of the equation, from both these causes, 
for each month, — the sign of the first cause being placed before the other : — 

January -f- 4- February -f -f- March + + April H — May-j — June-1 July — \- 

August— + September 1- October November December 

These signs are true for the whole, or greater part of each month ; while, fur 
a few days of some, they must be altered. They may be easily verified by the 
annexed diagram (Figure 36), in connection with Figure 35* 

As the Earth (Figure 36) is moving in one part of the ecliptic, the sun ap- 
pears to move in the other ; so that when the Earth is in the sign Aries, the Sun 
appears in the opposite sign Libra. The apparent velocity of the Sun, corres- 
ponds with the real velocity of the Earth, at the same time, except that, as to 
place, it is reversed. Thus, when the Earth is moving, with its greatest velo- 
city, through the perihelion, the Sun appears to move, with the same velocity, 
through the aphelion. The annexed diagram, representing the apparent places of 
the Sun alone, has been drawn in accordance with its motions. Let the line A P 
represent the apsis line of the Earth's orbit; A being the aphelion, and P the 
perihelion, the longitude of the latter being about 99k degrees. Let also S rep- 



Fig. 36. 




resent the real place of the San, and the centre of the Orbit. ABCD, etc., 
will then represent the apparent places of the Sun, for the corresponding 
months, and A b cd, etc., its mean places, for the same months. The spaces 
A B, B C, CD, etc., indicate unequal portions of apparent time, and A b. b c, c d, 
etc., equal portions of mean time, as kept by the clock. It will be seen that 
these do not agree ; but that, from A to B, the sun moves faster than the clock 
by B b ; and that, as it moves towards P, this difference increases, until at P, 
they coincide, and the equation vanishes. In the other half of the ecliptic, the 
same appearances are presented, except that the Sun keeps behind the clock, 
until at arrives at A, when the equation again vanishes. From this, it will be 
easily understood, why this cause, acting alone, would make the Sun arrive at 
the meridian after noon, as shown by the clock, from January to July, and be- 
fore noon, from July to January. 



78 



ASTRONOMY. 



CHAPTER XXII. 



PRECESSION, ETC. 



The Precession of the Equinoxes, is a gradual falling 
back of the equinoctial points, from east to west. 

The amount of Precession, is fifty seconds every year. 

The Equinoxes make a complete revolution on the 
Ecliptic, in about 26.000 years. 

The motion of the Equinoxes, causes the Pole of the 
Equinoctial to revolve around the pole of the Ecliptic. 

In about 13,000 years, the Earth's axis, instead of 
pointing to the North Star, as at present, will point 47 
degrees from it. 

The Precession of the Equinoxes, is caused by the 
attraction of the Sun and Moon, acting upon the excess 
of matter at the Equator. 

• Fig. 37. 







Thas (Figure 37), the attraction of the Sun, acts obliquely on the excess of 

matter, at E and E'. and tends to draw it, towards the plane of the ecliptic. 

^Vere the Earth at rest, the effect of this would be, to shift the position of the 



What is the precession of the equinoxes ? What is its amount ? In what 
time do the equinoxes complete a revolution ? What does this motion cause ? 
In 13,000 years, where will the axis point ? By what is precession caused ? 



ASTRONOMY. 79 



Earth, drawing the equator E E' to the ecliptic, and finally, causing the two 
circles to coincide. But, in consequence of the rotation of the Earth on its axis, 
the effect is merely to cause the equinoctial, apparently, to slide around, on the 
ecliptic, the two circles remaining at the same inclination ; and the pole P, to 
revolve around the pole P ; , as the p% of a top moves round, when its motion is 
becoming spent 

The Tropical Year, is the time which elapses from the 
Suit's leaving one of the equinoxes, until it arrives at 
the same agaiu. 

The Sidereal Year, is the time which elapses from the 
Sun's leaving a star, till it returns to the same again. 

On account of the Precession of the Equinoxes, the 
Tropical year is about twenty minutes shorter than the 
Sidereal year. 

This will be evident, from an inspection of Figure 36. For, suppose the Sun 
to be at D, while moving towards P ; and that, during a complete revolution, 
the point D moves in an opposite direction to d; the Sun will return to D sooner 
than otherwise, by the distance D d. 

The Line of Apsides of the Earth's orbit, has a slow 
motion, from west to east; completing a revolution, in 
about 100,000 years. 

The Annual motion, is about twelve seconds. 

The Longitude of the Perihelion, increases annually 
about sixty-two seconds. 

Thus, the line P A (Figure 36), moves round, in the order of the signs, twelve 
seconds every year -; but, as the first point of Aries, on account of the precession 
of the equinoxes., moves in an opposite direction,, and longitude is reckoned from 
this point, twelve seconds added to the amount of precession, will give the an- 
nual change of the perihelion. This point is now, in about the tenth degree of 
Cancer. In the year 1248, it was exactly at the summer solstice ; and about 
5500 years ago, at the first point of Aries. 



What is the tropical year ? "What is the sidereal year ? What is the differ- 
ence between them ? What motion has the line of apsides 1 How great is 
the annual motion 1 How much does the longitude of the perihelion increase 
annually 1 



ASTBOXOMY. 



CHAPTER XXIII. 

COMMS. 

Comets are bodies which revolve around the Sun, in 
very eccentric orbits ; and are generally accompanied by 
a long train of light. 

A Comet generally consists of three parts ; the Nu- 
cleus, the Envelope or Coma, and the Tail. 

The Nucleus is the bright spot, seen in the centre of 
the comet. 

The Envelope is the hazy or nebulous substance, 
which surrounds it. 

The Tail is the train of light, accompanying it. 

The exact number of comets belonging to the Solar 
System, is not known ; but more than 500 have been 
observed, since the Christian era. 

The Elements- of only ISO of these, have been cal- 
culated. 

Comets revolve, both in an eastward and a westward 
direction ; and their orbits are situated, at every inclina- 
tion to the ecliptic. 

Comets are supposed to be collections of gaseous 
matter ; as their density is much less than that of the 
planets. 



What are eomets ? Of how many parts does a comet consist ? What is the 
nucleus ? What is the envelope ? What is the tail ? How many comets are 
there belonging to the solar system ? Of liow many have the elements been 
calculated ? How do comets revolve ? What are comets supposed to be ? 



* By the elements of a planet or comet, are meant the figure, dimensions, and posi- 
tion of its orbit. 



ASTRONOMY. 81 



The Tail of a comet, is generally on the side from the 
Sun, and is of a bent or curved form. 

Some Comets are destitute of any tail; and others 
have more than one. 

The Comet of 1744, had six tails, spread out in the 
form of a fan. 

The Yelocity of a comet, like that of the planets, in- 
creases as it approaches the Sun. 

The Comet of 1680, moved 880,000 miles an hour. 

The Time which a Comet takes, to revolve around the 
Sun, is not always the same, at different times. 

This is occasioned, by the disturbing influence of the 
planets. 

Comets are known to consist of only a small quantity 
of matter, by their not disturbing the planets which they 
approach, but being very much disturbed by them. 

The Tails of some comets, extend an immense dis- 
tance in the heavens. 

The Comet of 1680, had a tail extending about 120 
millions of miles. 



On which side is the tail ? Have all comets tails ? "What is said of the 
comet of 1744 ? "When does the velocity of a comet increase ? How great 
Avas the velocity of that of 1680 ? Does a comet revolve around the sun always 
in the same time ? Why not ? How are comets known to consist of a small 
quantity of matter? How far do their tails extend? How far did that of 
1680? 



4* 



82 ASTRONOMY. 



CHAPTER XXIY. 

THE FIXED STARS. 

The Fixed Stars are those bodies which always appear, 
in the same relative situations. 

Fixed Stars are supposed to be luminous bodies; be- 
cause, if they borrowed their light from any other lumi- 
nous body, that body would also be visible. 

They are believed to be Suns, belonging to systems 
of planets, like the Solar S} 7 stem. 

They are of different magnitudes ; and some have been 
calculated to be much larger than the Sun. 

The Stars have no disc, presenting only the appear- 
ance of luminous ijoints. 

The distance of the nearest fixed star, (Aljjha Centauri,) 
has been calculated to be, about twenty trillions of miles 
from the Sun, or about 200,000 times as far as the 
Earth. 

The distance of the next nearest, (61 Cygni,) is sup- 
posed to be three times as far as Alpha Centauri. 

From the latter, light, travelling at the rate of 
192,000 miles in a second, would require more than 
nine years to reach the Earth. 

From the Pole Star, light requires more than twenty 
years to reach the Earth. 



What are the fixed stars ? Why are they supposed to be luminous ? What 
are they believed to be \ Are they of the same size ? Have they any disc ? 
What is the distance of the nearest ? What is that of the next? In what time 
would light pass from the latter to us ? In what time from the pole star ? 



ASTRONOMY. 83 



The distances of only seven of the Fixed Stars, have 
been ascertained, with any degree of precision. 

It is impossible to estimate the member of the Fixed 
Stars; they doubtless amount to millions of millions. 

Variable Stars, are those which do not always shine 
with the same brightness. 

This is accounted for by supposing that they revolve on axes, and present to 
us sides differing in brightness ; or that their light is obscured by the interposi- 
tion of planets, revolving around them. 

Temporary Stars, are those which have suddenly ap- 
peared in the heavens, and, after a certain time, as sud- 
denly disappeared. 

Ten new stars appeared, and thirteen disappeared 
during the last century. 

No satisfactory theory has been advanced to account for these wonderful phe- 
nomena. The fact, that some stars have suddenly shone out, with such an 
extraordinary degree of brilliancy, as to be seen at mid-day, and, after a short 
time, have faded away and disappeared, would seem to indicate some extensive 
conflagration on their surface, or their entire destruction by fire. This is, ac- 
cordingly, the opinion of many ; while others suppose that these bodies may be 
revolving in ellipses, and, at one time, approach so near as to be visible in the 
day time; while at others, they recede to the farthest points of their orbits, and 
thus entirely vanish from our view. 

Nebulous Stars, are those which are surrounded by a 
hazy appearance, like the nucleus of a comet. 

Multiple Stars, are those which, on being viewed with 
a telescope, appear to consist of two or more Stars. 

Double Stars, are those which are separated by the 
telescope into two Stars. 

Several stars appear double, although at immense distances from each other, 



Of how many stars, have the distances been ascertained ? What is the num- 
ber of the stars ? "What are variable stars ? What are temporary stars ? How 
many appeared and disappeared during the last century ? What are nebulous 
stars ? What are multiple stars ? What are double stars ? 



84 ASTROXO M Y. 



on account of their being situated nearly in the line of vision ; these are said to 
be optically doable. Others are actually connected, and revolve one around 
the other ; there are said to be physically double. 

Binary Systems, are double stars, one of which re- 
volves around the other ; — or both revolve around their 
common centre of gravity. 

Binary Systems sometimes exh'.bit Stars, of different 
colors. 

Between forty and fifty have been discovered. 

Their periods of revolution, vary from forty to sixteen 
hundred years. 

The Galaxy or Milky Way, is a faint zone of light 
encompassing the heavens, and discovered, by the tel- 
escope, to consist of vast numbers of Stars. 

A Cluster is a number of stars collected in a certain 
space. 

Nebulae are certain cloudy appearances, seen in the 
heavens ; most of them supposed to consist of vast num- 
bers of Stars. 

They may be divided into two classes ; viz., Eesolva- 
ble, and Irresolvable. 

Resolvable Nebulae, are those which are supposed to 
consist of vast numbers of Stars, so far distant as to 
appear like spots of cloud. 

Irresolvable Nebulae, are those which the most power- 
ful telescopes, have failed to resolve into Stars. 

The latter are supposed to be luminous matter, con- 
densing into solid bodies, like the Sun. 



What are binary systems ? What do they sometimes exhibit ? How many 
have been discovered? What are their periods of revolution? What is the 
galaxy or milky way? What is a cluster? What are nebulae? How many 
classes are there ? What are resolvable nebulas ? What are irresolvable 
nebulas ? What are the latter supposed to be ? 



ASTRONOMY. 85 



Nebulae which resemble the disc of a planet, are called 
Planetary Nebulae. 

Those, which have the appearance of a Star, sur- 
rounded by luminous matter, are called Stellar Nebulae. 

The Galaxy, or Milky Way, is supposed to be a 
nebula, or cluster, of which the Sun is a member. 

Its shape is supposed to resemble an immense ivheel, 
the Sun being situated comparatively near the centre. 

All the Stars in this cluster, including the Sun, are 
believed to revolve around their common centre of 
gravity. 

The Universe is supposed to consist of an infinite 
number of Clusters similar to that, of which the Sun is a 
member, and situated at immense distances from each 
other. 



CHAPTER XXV. 

CONSTELLATIONS. 

A Constellation is a number of Stars, included in 
a certain space. 

There are ninety-three Constellations set down on 
most globes. 

The Constellations are divided into three classes, viz., 
Northern, Southern, and Zodiacal. 



What are planetary nebulae ? What are stellar nebulse ? What is the gal- 
axy supposed to be ? What is its shape ? What revolution have the stars of 
this cluster ? Of what does the universe consist ? 

What is a constellation ? How many are there ? Into how many and what 
classes are they divided ? 



86 ASTRONOMY. 



The Northern Constellations, are those which lie north 
of the Zodiac. 

The Southern Constellations, are those which lie south 
of the Zodiac. 

The Zodiacal Constellations, are those which lie within 
the Zodiac. 

The Northern are thirty-four in number, the Southern 
forty-seven, and the Zodiacal, twelve. 

The names of the Constellations of the Zodiac, are the 
same as those of the Signs. 

In consequence of the precession of the equinoxes, 
the Signs have fallen hack of the Constellations, about 
thirty-one degrees. 

They corresponded twenty-two centuries ago. 

Stars are classified, according to their apparent size or 
brightness. 

The brightest stars, are said to be of the first magni- 
tude, and the least that are visible to the naked eye, are 
of the sixth. 

Telescopic Stars, are those which can only be seen 
with a telescope. 



What are the northern constellations 1 What are the southern ? What are 
the zodiacal ? What is the number of each ? What are the names of the zodi- 
acal ? Do the signs and constellations correspond ? When did they correspond ? 
How are stars classified ? How are the brightest stars distinguished ? What 
are telescopic stars ? 



ASTKONOMY. 



87 



The following is a list of the Constellations, with the prin- 
cipal Stars in each. The figure after the Star denotes its 
magnitude. 

THE ZODIACAL CONSTELLATIONS. 





NUMBER 


NAMES OF THE PRINCIPAL 




OF STARS. 


STARS. 


Aries, The Ram, .... 


. 66 . . 


Arietis 2. 
( Aldebaran 1, The Pleiades, 


Taurus, The Bull, . . . 


. 141 . . 


( The Hyades. 


Gemini, The Tic ins, . . 


. 85 . . 


Castor 1, and Pollux 2. 


Cancer, The Grab, . . . 


. 83 ■ 




Leo, The Lion, .... 


. 95 . . 


Ttegulus 1. 


Virgo, The Virgin, . . 


. 110 . . 


^ Spica Virginis 1, Vinde- 
\ miatrix 2. 


Libra, The Balance, . . 


. 51 




Scorpio, The Scorpion, 


. 44 . . 


Antares 1. 


Sagittarius, The Archer, 


. 69 




Capricornus, The Goat, . 


. 51 




Aquarius, The Water-bearei 


, 108 . . 


Seheat 3. 


Pisces, The Fishes, . . . 


. 118 





THE NORTHERN CONSTELLATIONS. 

NUMBER NAMES OF THE PRINCI- 

OF STARS. PAL STARS. 

Andromeda, 66 . . Miracli 2, Almaach 2. 

Aquila, The Eagle, and ) . . 71 . . Atair 1. 

Antinous, ) 

Asterion et Chara or ) 05 

Canes Yenatici, The Greyhounds, ) 

Auriga, The Charioteer, . . . . 66 . . Oapella 1. 

Bootes, . 54 . . Arcturus 1, Mirach 3. 

Camelopardalus, The Camelopard, 58 

Cassiopeia, 55 . . Schedar 3. 



ASTRONOMY. 



NUMBER NAMES OF THE PR1NCI- 

OF STARS. PAL STARS. 

Cepheus, 35 . . Alderamin 3. 

Coma Berenices, Berenice's Hair, . 43 

Coe Caroli, Charles's Heart, ... 3 

Corona Borealis, The Northern 

Croicn, 21 . . Alphacca 2. 

Cygxus, The Sican, 81 . . Deneb 1. 

Delphinus, The Dolphin, .... 18 

Draco, The Dragon, 80 . . Eastaben 2. 

Equulus, The Little Horse, ... 10 

Hercules et Cerberus, . . . . 113 . . Eas Algetlii 3. 

Lacerta, The Lizard, 16 

Leo Minor, The Little Lion, . . . 53 

Lynx, The Lynx, 44 

Lyra, The Harp, 22 . . Yega 1. 

Mons M^enalus, The Mountain Mm- 

nalus, 11 

Musca, The Fly, 6 

Pegasus, The Flying Horse, . . . 89 . . Markab 2, Scheat 2. 

Perseus, et Caput Medusae, . . . 59 . . Algenib 2, Algol 2. 

Sagitta, The Arrow, 18 

Scutum Sobieski, SohieslPs Shield, . 8 

Serpens, The Serpent, G4 

Serpentarius, The Serpent-bearer, . 74 . . Eas Alhagus 2. 

Taurus Poniatowski, PoniatowsMs 

Bull, 7 

Triangulum, The Triangle, ... 11 

Triangulum Minus, The Little Tri- 
angle, 5 

Ursa Major, The Great Bear, . . 87 . . Dubhe 1, Alioth 2, 

Benetnach 2. 

Ursa Minor, The Little Bear, . . 24 . . Pole Star 2. 

Yulpecula et Anser, The Fox and 

the Goose, 37 



ASTRONOMY. 


89 


THE SOUTHERN 


CONSTELLATIONS. 




NUMBER 


NAMES OF THE PRINCI- 




OF STARS. 


PAL STARS. 


Aprs or Avis Ixdica, The Bird of 




Paradise, 


. . 11 




Aea, The Altar, . . . . . 


. . 9 


. Canopus 1. 


Aego Nayis, The Ship Argo, . 


. . 64 . 


BeAXDEXBEEGIEM SCEPTEEM, 


The 




Sceptre of Brandenburgh, . 


. . 3 




Oanis Ma joe, The Great Dog, 


. . 31 . 


Sirius 1. 


Caxis Mixoe, The Little Dog, 


. . 14 . 


Procyon 1. 


Cextaeees, The Centaur, . . 


. . 35 




Cetus, The Whale, .... 


. . 97 . 


. Mencar 2. 


Chaaleliox, The Chamelion, . 


. . 10 




Ciecixus, The Compasses, . . 


. . 4 




Columba Noachi, Noah's Dove, 


. . 10 




Coeoxa Austealis, The Southern 




Crown, 


. . 12 




Coeyus, The Croic, .... 


. . 9 . 


Algorab 3. 


Oeatee, The Cup, .... 


. . 31 . 


. Alkes 3. 


Ceex, The Cross, 


. . 6 




Doeoda, or Xiphias, The Sicord-fsh, 7 


Equtjleus Pictoeees, The Painter's 




Easel, 


. . 8 




Eeidaxes, The River Po, . . 


. . 84 . 


. Achernar 1. 


Foexax Chemica, The Furnace 


. . 14 




Gees, The Crane, . . . , 


. . 13 




Hoeologioi, The Clock, . . 


. . 12 




Hydea, The Water-Serpent, . 


. . 60 . 


. Cor Hydra 1. 


Hydees, The Water-Snake, . 


. . 10 




Ixdes, The Indian, .... 


. . 12 




Lepes, The Hare, 


. . 19 


Lupes, The Wolf 


. . 24 


Machixa Pxeematica, The 


Air- 




Pump, 


. . 3 





90 ASTRONOM Y. 


NUMBER 


names of the princi- 


OF 


STARS. 


pal STARS. 


Miceoscopiem, The Microscope, . . 


10 




Moxoceeos, The Unicorn, .... 


31 




Moxs Mexs^e, The Taole- Mountain, 


30 




Muse a ArsTEALis, The Sou thern-Fly, 


4 




Xoema Erci.iDis, Euclid's Square. . 


12 




Octaxs Hadleiaxus, Hartleys Oc- 






tant, 


43 




Officixa Sculptoeia, The Sculptor s 




Shop, 


12 




Oeiox, 


78 . 


Betelgnez 1, Rigel 1, 
Bellatrix 2. 






Pato, The Peacock, 


14 




Phcexix, 


13 




Piscis Notius, The Southern Fish, . 


24 . 


Fomalhaut 1. 


Piscis Yolaxs, The Flying Fish, . 


8 




Peaxiteles, or Cela Sculptoeia, 






The Engraver's Tools, .... 


16 




Pyxis X autica, The Mariner's Com- 






pass, 


4 




ReticulusRhomboidalis, ThePJtom- 






ooiclal Net, 


10 




Robue Caeoli, Charles's Oak, . . 


12 




Sextaxs, The Sextant, 


41 




Telescopium, The Telescope, . . . 


9 




Tone ax, The American Goose, . . 


9 




Teiaxgeloi Austeale, The South- 






ern Triangle, 


5 




TABLE OF PRINCIPAL STARS. 


Acheexae, in Eridanus, or 


the River Po. 


Acubexs, in the claw of Cancer. 




Aldebaeax, in the eye of T 


aurus. 




Algol, in the head of Medu 


sa. 





ASTRONOMY. 91 



Alioth, in the tail of Ursa Major. 

Almaach, in the foot of Andromeda. 

Alphacca, in the Northern Crown. 

Albeccabae, the Pole Star, in Ursa Minor. 

Antaees, in the heart of Scorpio. 

Aeietis, in Aries. 

Ataie, in Aquila, the Eagle. 

Aeqteees, in Bootes. 

Bellateix, in the west shoulder of Orion. 

Betelgeez, in the east shoulder of Orion. 

Caxopes, the bright star in Argo. 

Capelea, the bright star in Capricorn. 

Castoe and Pollux, in the head of Gemini. 

Coe Caeoli, the double star in the Greyhounds. 

Dexeb, in the tail of Cygnus. 

Fomaehaut, in the Southern Fish. 

Htades, a cluster of stars in Taurus. 

Maekab, in the wing of Pegasus. 

Mexeae, in the jaw of the Whale. 

Mieach, in the thigh of Bootes. 

Mieach, in the girdle of Andromeda. 

Pleiades, a cluster in Taurus. 

Peocyox, in Canis Minor. 

Eastaben, in the head of Draco. 

Eas Algethi, in the head of Hercules. 

Eas Alhages, in Serpentarius. 

Eegeles, in the heart of Leo. 

Eigel, in the foot of Orion. 

Scheat, in Aquarius. 

Schedae, in the breast of Cassiopeia. 

Scheat, in the thigh of Pegasus. 

Sieies, in Canis Major. 

Spica Vibginis, in the sheaf of Yirgo, 

Vega, in Lyra. 

Yixdemiateix, in Yirgo. 



PAET II. 
THE ARTIFICIAL GLOBES. 



CHAPTER I. 

APPENDAGES TO THE GLOBES. 

The Brazen Meridian is a circle of brass, which 
encompasses the artificial globe from pole to pole. 

It is intended to represent, the Meridian of any place 
on the globe. 

It is divided into degrees, on one semicircle, from the 
Equator towards the Poles ; and on the other, from the 
Poles towards the Equator. 

The Hour Circle is a small circle, described round the 
North Pole, with the hours of the day marked on it. 

The Wooden Horizon is a circular plane, encompass- 
ing the artificial globe, to represent the Rational Horizon. 

The Quadrant of Altitude, is a flexible strip of brass, 
graduated upwards from to 90 degrees, and downwards 
from to 18 degrees. 

It is used to measure distances, on the artificial globe. 



What is the brazen meridian ? What does it represent ? How is it divided ? 
What is the hour circle ? What is the wooden horizon ? What is the quad- 
rant of altitude ? For what is it used ? 



ASTRONOMY. 93 



The Mariners Compass, is a representation of the 
horizon, and is divided into 82 equal parts, called points 
of the Compass. 

The four cardinal or principal points of the horizon, 
are North, East, South, and West, 

The Angle of Position, between two places, is an 
angle, formed at the zenith of one of the places, by the 
meridian of that place, and a vertical circle) passing 
through the other place, 

It is reckoned on the wooden horizon. 

Rhumbs are 82 divisions of the horizon } called the 
points of the compass. 

A Rhumb Line is a line which a ship describes, while 
she sails on the same point of the compass* and cuts all 
the meridians, at the same angle* 



CHAPTEB It. 

PROBLEMS FOR THE TERRESTRIAL GLOBE. 
PROBLEM I. 

To find the latitude and longitude of any given 'place. 

RuLE b — Bring the given place to the graduated side 
of the brazen meridian, which is numbered from the 
equator towards the poles ; and the degree of the merid- 



What is the mariner's compass ? What are the cardinal points 1 What is 
the angle of position between any two places! On what is it reckoned? 
What are rhumbs f What is a rhumb line 1 



94 



ASTEONOMT. 



ian, over the place, will be the latitude ; and the degree 
of the equator, under the meridian, will be the longitude. 

On Wilson's Globes, there are two rows of figures above the equator. When 
the place lies on the east side of the meridian of London, the longitude is found 
on the upper line ; and when it is on the west side, on the lower line. 

EXAMPLES. 

Find the latitude and longitude of the following 
places : 



1. New York, 

2. Amsterdam, 

3. Mobile, 

4. Louisville, 

5. Columbus^ 

6. Paris, . . 

7. Rio Janeiro, 

8. Quito, 

9. Delhi, Asia, 

10. Valparaiso, 

11. Stockholm, 

12. Jeddo, 

13. Tobolsk, . 

14. Mexico, 

15. Pekin, 

16. London, 

17. East Cape, 

18. North Pole, 

19. Cape Horn. 

20. Morocco. 

21. Naples. 



Answer, 41° N. 74° W. 
52^ N. 5° E. 
31° N. 88° \V. 
38i° N. 86° W. 
40° N. 83° W. 
49° N. 2i° E. 
22° S. 43° W. 
78° W. 

28£° N. 78° E. 
33° S. 71° W. 
59i° N. 18° E. 
36° N. 140° E. 
58° N.68£° E. 
19i°N. 100° W. 
40° N. 116° E. 
51£° N. 
66£°N.170°W. 
90° N. 

22. Calcutta. 25. St. Petersburgh. 

23. Vienna. 26. Madrid. 

24. Smyrna. 27. Lima. 



ASTRONOMY. 95 






PROBLEM II. 


The latitude 


and 


' longitude of a 'plate being given, to find 
the place. 


Rule.— ^Find the degree of longitude on the equator ; 


bring it to 


the brazen meridian, and under the given 


degree of latitude, on the meridian, will be the place 


required. 




EXAMPLES. 


Find the 


places, whose latitude and longitude are as 


follows : 






30° tf. 


90° 


W. . . i . Answer. New Orleans. 


43° K 


72° 


W " Concord. 


23£° N. 


57° 


E. .... " Muscat. 


50° N. 


14° 


E*, . 4 * ' ' i " Prague. 


40° N. 


75° 


W. . . . „ " Philadelphia. 


39° N. 


84° 


W " Cincinnati. 


0° 


78° 


W. . . . . " Quito. 


39° BTi 


77° 


W " Washington. 


12° S. 


77° 


W. .... " Lima. 


46° T$. 


6 9 


E. t . . * " Geneva;. 
PROBLEM III. 


To find the difference of latitude or longitude between any 






two places. 


Rule.— Find the latitude or longitude of both places; 


if alike, subtract them ; if unlike, add them ; and the 


sum, or difference, wilkbe the answer required. 


Note. — By alike is meant on the same side of the equator, or first meridian ; 


by unlike, on different 


sides* 



ASTRONOMY. 



EXAMPLES 

Find the difference of latitude and longitude between 
the following places i 

1. Alexandria and Amsterdam, Answer, Lat. 21®, Long. 

2. Athens and Berlin, ... ' 



Lat. 21®, 


Long. 


2g°. 


Lat. 14°, 


Long. 


10°. 


Lat. 3°, 


Long. 


89°. 


Lat. 90°, 


Long. 


114°. 


Lat. 81°, 


Long. 


61°. 


Lat, 60°, 


Long. 


93°. 


Lat. 86°, 


Long. 


G5°. 


Lat. 180 s 







3. Rome and Washington, 

4. Moscow and Botany Bay, . 

5. Stockholm and Rio Janeiro, 

6. Vienna and Lima, . . k 

7. Dublin and Valparaiso, . . 

8. North and South Pole, . > 

9. New York and Pekin, . . 



PROBLEM IV. 
To find all ike places lOhim have the same latitude 
as a given pla.ce. 

Rule. — Bring the given place to the graduated side 
of the brasen. meridian, and observe its latitude ; turn 
the globe round, and all the places which pass under the 
same degree of the meridian, will be those required. 

EXAMPLES. 

Find the principal places which have the same, or 
nearly the same, latitude as— 

1. Indianapolis. — Answer. Columbus, Philadelphia, Toledo, 

Minorca, Erzerum, Bucharia, Samarcand, 
Pekin. 

2. Boston. . *— Answer. Leon, Ajaccio, Rome, Derbent, 

Khiva, Matsmay, Cape Orford, Chicago, 
Detroit, Buffalo, Albany. 



ASTRONOMY. 97 



3. Lima. . » — Answer. St. Salvador, St. Felipe xle Ben- 

gutla. Lake Maravi, Comoro Isles, Cape 
Ambro, Gulf of Carpentaria, Navigator's 
Isles, 

4. Quito. , . - — Answer. Johannes Island, St. Thomas Island, 

Sumatra, Borneo, Celebes, Galipagos 
Isles. 

5. Havana. . — Answer. Bahama Isles, Great Desert of Sa- 

hara, Assouan, Muscat, Gulf of Cutch, 
Canten, Formosa, Anson's Archipelago, 
Cape St. Lucas, Zacatecas. 

6. North Cape, 9. Constantinople. 12. London. 

7. Jeddo. 10. Rio Janeiro. 13. Lisbon. 

8. St. Petersburg!!. 11. Bombay, 14. Mexico. 

PROBLEM V. 

To find all those places which, have the same longitude as 
■any given place. 

Rule. — Bring the given place to the graduated side 
of the brasen meridian, and all places under the merid- 
ian, from pole to pole, will be those required. 

EXAMPLES, 

Find all places having the same, or nearly the same, 
longitude as— 

1. Lima. . . - — Anstoer. Lancaster Sound, Hudson's Straits, 
East Maine, Kingston, Harrisburgh, Bal- 
timore, Washington, Richmond, Cape 
Lookout, Eleuthera, Kingston in Jamai- 
ca, Popayan, 



ASTRONOMY, 



2. London. . — Answer. Havre, Bordeaux, Valencia, Oan, 

Gulf of Guinea. 

3. Rio Janeiro. — Answer. Greenland, Cape Farewell, Maran- 

ham, Villa Rica. 

4. New Orleans. — Answer. Barrow's Strait, Regent's Inlet, 

Wager River, Western part of Lake 
Superior, St. Louis, Yucatan, Guatirnala, 
Galipagos Isles. 

5. Napleb. . — Answer. Spitzbergen, Luffoden Isles, Carls- 

erona, Trieste, Lipari Isles, Syracuse, 
Mourzouk, Lake Tchad, St. Salvador, 
Desert of Cimbebas. 

6. Pekin. 9. Cape Good Hope. 12. Mexico. 

7. Calcutta, 10. Dublin. 13. Constantinople. 

8. Quebec. 11. Stockholm, 14. Cairo. 

PROBLEM VI. 

To find the distance between any two places on the globe. 

Eule. — Lay the graduated edge of the quadrant of 
altitude* over both places, so that the division marked 
0, may be on one of them ; and the number of degrees 
between them, reduced to miles, will be the distance 
required. 

Note. — If geographic miles ere required, multiply the degrees by 60 ; if 
statute miles, 69£. 



* The use of the quadrant of altitude, may be dispensed with in this problem, by 
laying a slip of paper over both places, and marking the distance between them ; then 
placing it exactly over the equator, and the number of degrees included in the dis- 
tance marked off, will be the answer in degrees. Then reduce as before. 



ASTRONOMY. 99 



EXAMPLES. 

Find the direct distance, in geographic and statute 
miles, between the following places : 

1. North Cape and Cape Matapan ? — Answer. 2,100 Geo- 
graphic miles ; 2,4 3 2£ Statute miles. 

2. Cape of Good Hope and Van Diemen's Land? 

3. Cape Blanco, and Cape St. Roque ? 

4. St. Petersburgh and Astracan ? 

5. Calcutta and Pekin ? 

6. Paris and Vienna ? 

7. Savannah and New York ? 

8. New Orleans and Baltimore ? 

9. Cape Tamura and Cape Romania? 
10. San Francisco and New York? 

PROBLEM VII. 

To find the Antoeci of any place. 

RuLEv — Bring the given place to the brazen meridian, 
and find its latitude ; and under the meridian, at the 
same degree of latitude, in the opposite hemisphere, will 
be the place required. 

EXAMPLES. 

Find the Antoeci of the following places : 

1. Cape Horn, . Answer. Central part of Labrador. 

2. New York, . " Northern part of Patagonia. 

3. Jeddo. 6. Trinidad. 9. Lima. 

4. Havana. *7. Pekin. 10. Bombay. 

5. London. 8. Savannah. 11. Lassa. 



100 ASTRON03I Y. 



PItOBLEM VIII. 

To find the Penoeci of any places, 

Rule. — Bring the given place to the brazen meridian, 
note its latitude-, and set the index to twelve j then turn 
the globe till the index points to the other twelve ; and 
under the same degree of latitude, will be the place 
required. 

EXAMPLES. 

Find the Perioeci of the following places j 

1. Bay of Bengal, Answer. Caribbean Sea. 

2. London, . . . . * . . " Fox Islands. 

3. Naples. 6. Mexico. 9. Tobolsk. 

4. Baltimore. 7. Paris. 10. Canton. 

5. Cape Horn. 8. Montreal. 11. Cape Town. 

PROBLEM IX. 

To find the Antipodes of any place, 

Rule. — Bring the given place to the brass meridian, 
note its latitude, and set the index to twelve; then turn 
the globe round until the index points to the other 
twelve ; and under the same degree of latitude in the 
opposite hemisphere, will be the place required. 

EXAMPLES. 

Find the Antipodes of the following places : 

1. Quito, Answer. Sumatra. 

2. Sandwich Islands, . . " Desert of Cimbebas. 

3. New York. 5. Cuba. 7. Constantinople. 

4. London. 6. New Zealand. 8. Lisbon. 



ASTRONOMY. 101 



PROBLEM X. 

The hour of the day being given at any place, to find what 
time it is at any other place. 

Rule 1. — Bring the place, at which the time is given, 
to the brazen meridian, set the index to the given hour, 
turn the globe till the other place comes to the meridian, 
and the index will show the hour required. 

Note. — If the place, at which the time is required, be east of the given place, 
turn the globe westward ; if west, turn it eastward. If it be east, the time is 
later; if west, earlier than that at the given place. 

Rule 2. — Find the difference of longitude, between 
the two given places ; multiply the degrees by four, and 
the product will be minutes of time ; the minutes multi- 
plied by four, will give seconds of time; reduce to 
hours, and it will give the difference of time. If the 
time required be earlier, subtract it, if later, add it, to 
the given time, and the result will be the answer re- 
quired. 

EXAMPLES. 

1. "When it is noon at New York, what o'clock is it at London ? 
— Answer. 5 o'clock, p. m. (nearly.) 

2. When it is 10 o'clock, a.m., at St. Peteivburgh, what o'clock 
is it at Mexico? — Answer. 1 hour 20 min., a.m. 

- 3. When it is midnight at New York, what o'clock is it, at 
Calcutta, Madrid, Moscow, New Orleans, 

Lima, Cape Horn, Pekin, Botany Bay? 

4. When it is 8 o'clock, a. m., at Vienna, what time is it at 
Washington, Faris, . Constantinople, 

Sandwich Islands, Canton, Archangel \ 



102 ASTRONOMY. 



PROBLEM XL 

The hour of the day being given at any place, to find all the 
places at which it is any other given hour. 

Rule. — Bring the given place to the brazen meridian, 
and set the index to the hour of that place ; then turn 
the globe, till the index points to the other given hour ; 
and all places under the meridian will be those required. 

Note. — Turn the globe, as in the previous Problem. 
EXAMPLES. 

1. When it is 3 o'clock, a.m., in Philadelphia, at what places is 
it 8 o'clock, a. m. ? — Answer. London, Havre, Bordeaux, and 
Valencia ? 

2. When it is midnight at Washington, at what places is it 1 
o'clock, a. m. ? 

3. When it is noon at Paris, where is it midnight ? 

4. When it is *l o'clock, p.m., at Lima, where is it noon ? 

5. When it is noon at New York, where is it 4 o'clock, p. m. ? 

6. Where is it 7 o'clock, a. m. ? 

V. When it is half-past 3 o'clock in the morning* at Pekin, 
where is it half-past 1 in the afternoon ? 

PROBLEM XII. 

To find the Sun's place in the Ecliptic, and longitude for any 
day in the year. 

Bule. — Look for the given day of the month, on the 
wooden horizon, and the degree corresponding to it, in 
the circle of signs, will be the Sun's place in the ecliptic 
for that day: find it on the ecliptic; and the number of 



ASTRONOMY. 103 



degrees, between it, and the first point of Aries, will be 
the Sun's longitude. 

EXAMPLES. 

Find the Sun's place, and longitude, for each of the 
following days : 

1. June 21st. — Answer. Place, 1st degree of Cancer, Lon- 

gitude, 90°. 

2. February 22cL — Answer. Place, 4£ degree of Pisces, Lon- 

gitude, 337i°. 

3. December 22d. 6. January 1st. 9. September 18th. 

4. July 4th. 7. November 20th. 10. May 15th. 

5. March 21st. 8. April 18th. 11. August 25th. 

PROBLEM XIII. 

To find the Sun's declination for any day in the year. 

Rule 1. — Find the Sun's place in the ecliptic, and 
bring it to the brazen meridian ; and the degree of the 
meridian over it will be the declination. 

Rule 2. — Bring the analemma to the brazen merid- 
ian ; and the degree of the meridian, over the given day 
of the month, will be the Sun's declination, for that day. 

EXAMPLES. 

Find the Sun's declination, for the following days : 

1. April 15th. — Answer. 10 degrees Forth. 

2. December 2 2d. — il 23 £ degrees South. 

3. August 15th. 6. September 1st. 9. October 20th. 

4. January 28th. 1. June 21st. 10. September 23d. 

5. March 21st. 8. February 1st, 11. November 1st. 



104 A ST E ONO MY. 



PROBLEM XIV. 

To find what places have a vertical Sun 7 on any particular 
day of the year. 

Rule. — Find the Sun's declination, and note the de- 
gree on the brazen meridian; turn the globe around, 
and all places that pass under that degree, will be those 
required. 

EXAMPLES. 

What places have a vertical Sun on the following 
days ? — 

1. June 21st. — Answer. All places under the tropic of Cancer. 

2. March 21st. — " x\ll places under the equator. 

3. December 25th. 5. April 1st. 7. October 10th. 

4. July 4th. 0. January 20th. 8. May 1st. 

PROBLEM XV. 

To rectify the Globe for the latitude of a place, and Surfs 
place in the Ecliptic, for any given day. 

Rule. — Elevate the north or south pole, according as 
the latitude of the place is north or south, a number of 
degrees corresponding to the latitude; find the Sun's 
place in the ecliptic, for the given day, bring it to the 
brazen meridian, and set the index to twelve. 

PROBLEM XVI. 

The day of the month heing given, at any pariicxilar place, 
in the torrid or temperate zones, to find, at what time, the 
Sun rises and sets, and the length of the day and night. 

Rule. — Rectify the globe for the latitude of the place, 



ASTRONOMY. 105 



&c., by Problem XV. ; bring the Sun's place to the 
eastern edge of the horizon, and the index will show 
the hour of rising ; subtract it from twelve, and the dif- 
ference w~HJ be the time of setting. 

Double the time of the Sun's setting, and it will give 
the length of the day ; double the time of its rising, and 
it will give the length of the night. 

EXAMPLES. 

Find the time of the Sun's rising and setting, and the 
length of the day and night, at each of the following 
places, on the given day. 

1. London, July 17 th. — Ansioer. Sun rises at 4, and sets at 8, 

and the length of the day is 1 6 hours, 
that of the night 8. 

2. New York, September 23d. 6. Montreal, May 1st. 

3. Paris, January 1st. 7. Stockholm, August 18th. 

4. Washington, December 1st. 8. Lima, April 10th. 

5. Vienna, March 25th. 9. Naples, October 10th. 

PROBLEM XVII. 

To find the length of the longest and shortest days and nights, 
at any place, within the Torrid or Temperate zones. 

Rule. — Find the length of the day and night at the 
given place, when the Sun is in the first degree of Can- 
cer, if it be in north latitude, or when it is in the first 
degree of Capricorn, if the place be in south latitude, 
and it will give the length of the longest day. Subtract 
it from twenty -four, and the difference will be the short- 
est night. The shortest night at any place, is equal to 



106 ASTRONOMY. 



its shortest daj^, and its longest night to its longest 
day. 

EXAMPLES. 

Find the length of the longest and shortest day at 
each of the following places : 

1. New York. — Answer. Longest day, 14 hours, 5 G minutes; 

shortest clay, 9 hours, 4 minutes. 

2. Quebec. 7. Archangel. 12. New Orleans. 

3. Buenos Ay res. 8. Quito. 13. C. Good Hope. 

4. Canton. 9. Cape Horn. 14. Bombaj-. 

5. London. 10. Montreal. 15. Mexico. 

6. St. Peterslmrgh. 11. Botany Bay. 16. Ceylon. 

PROBLEM XVIII. 

To find those places within (he Torrid or Temperate zones, 
at which the longest day is of any particular length. 

Rule. — If the places to be found, be in the northern 
hemisphere, bring the first degree of Cancer to the 
meridian, and set the index to twelve; then turn the 
globe, until the index has passed over half of the given 
time ; raise or depress the north pole, until the first de- 
gree of Cancer is brought to the edge of the horizon, 
and the elevation of the north pole will show the latitude 
of the places required. If the places to be found be in 
the southern hemisphere, bring the first degree of Cap- 
ricorn to the meridian, and raise the south pole instead 
of the north. 

EXAMPLES. 

1. At what places in the northern hemisphere, is the length of 
the longest day, 164- hours? — Answer. All places in lat. 52° N. 



ASTRONOMY. 107 



2. At what places in the southern hemisphere, is the longest 
day, 19 hours? 

3. At what places in north latitude is it 16 hours ? 

4. At what places in north latitude is it 20 hours ? 

5. At what places in north latitude is it 23 hours ? 

6. At what places in south latitude is it 18 hours ? 

PROBLEM XIX. 

To find at what day of the month, constant day begins and 
ends, and its duration, at any place, within the North 
Frigid zone, 

Eule. — Bring the given place to the meridian, and 
find its distance from the north pole ; count the same 
number of degrees on the meridian from the equator, 
and mark the degree where the reckoning ends ; then 
turn the globe ; and the two points of the ecliptic which 
pass under that degree of the meridian, will be the Sun's 
place, at the beginning and end of constant day. Find 
the corresponding days, on the wooden horizon, and 
these will be the dates required. Calculate the number 
of days between these two dates, counting from the ear- 
lier to the later, and it will be the duration of constant 
day, at the given place. 

EXAMPLES. 

. Find the beginning, end, and duration of constant 
day, at each of the following places : 

1. North Cape ? — Answer. Begins May 15th ; ends July 20th ; 

duration *l 5 days. 

2. Northern extremity of Spitzbergen ? 

3. Cape Cevero, the northern extremity of Asia? 



108 ASTRONOMY. 



4. Kola, in the northern part of Lapland ? 

5. Lancaster Sound ? 

6. Winter Harbor, in Melville Island ? 
1. Disco Island ? 

8. North Pole ? 

9. Arctic Circle ? 

PROBLEM XX. 

To find the Surfs meridian altitude, for any day in the year, 
at any given place. 

Rule. — Rectify the globe for the latitude of the place, 
bring the Sun's place in the ecliptic to the meridian ; and 
the number of degrees on the meridian, from the Sun's 
place to the horizon, will be the altitude required. 

EXAMPLES. 

Find the Sun's meridian altitude, at the following 
places, on the days given : 

1. New York, June 21st. — Answer. 73 degrees (nearly.) 

2. London, December 22d. 1. Quito, July 1st. 

3. Washington, Sept. 23d. 8. Paris, February 18th. 

4. Boston, March 21st. 9. Malta, April 20th. 

5. Montreal, January 1st. 10. Rio Janeiro, Oct. 23d. 

6. Lima, June 5th. 11. Bombay, May 21st. 

PROBLEM XXI. 

To find the Surfs amplitude, on any given day, at any place. 

Rule. — Rectify the globe for the latitude of the place ; 
bring the Sun's place, in the ecliptic, to the eastern edge 
of the horizon ;. and the number of degrees, from the 



ASTRONOMY. 109 



Sari's place to the eastern point of the horizon, will be 
the amplitude of the Sun at rising; bring the Sun's 
place to the western edge of the horizon, and the num- 
ber of degrees to the west point, will be the amplitude 
of the Sun at setting. 

EXAMPLES. 

Find the Sun's amplitude, at the following places, on 
the daj^s given : 

1. London, 21st of June. — Answer, 39° 48', North. 

2. New York, 2 2d of December 2 

3. Philadelphia, 21st of May? 

4. Cape of Good Hope, 10th of July ? 

5. Cape Town, 1st of April ? 

6. Washington, 18 th of February? 
1. Mexico, 23d of September *? 

8. Lima, 2 2d of December? 

9. Quito, 21st of June? 

PROBLEM XXII. 

To find the Sun's altitude and azimuth, .at any place, for 
any given day and hour. 

Rule. — Bectify the globe for the latitude of the place, 
and screw the quadrant of altitude, over that latitude ; 
find the Sun's place in the ecliptic, bring it to the merid- 
ian, and set the index to twelve ; then, if the given time 
be before noon, turn the globe eastward ; if afternoon, 
turn it westward, till the index points to the given hour; 
bring the graduated edge of the quadrant of altitude to 
coincide with the Sun's place ; and the number of de- 
grees, on the quadrant, from the Sun's place to the 



110 ASTRONOMY. 



horizon, will be the altitude ; and the number of degrees 
on the horizon, from the north or south points of the 
meridian, to the graduated edge of the quadrant, will 
be the Sun's azimuth. 

EXAMPLES. 

Find the Sun's altitude and azimuth, at the following 
places, at the given time : 

1. New York, May 10th, 9 o'clock, a.m.? — Answer. Altitude, 
45|°; Azimuth, I07f° N., or 72i° S. 

2. London, May 1st, 10 o'clock, a.m.? — Answer. Altitude, 
47°; Azimuth, 136° X., or 44° S. 

3. Washiugton, June 21st, 8 o'clock, a.m.? 

4. Boston, December 5th, 3 o'clock, p.m. \ 

5. Charleston, May 12th, 10 o'clock, a. m. ? 
G. Madrid, January 20th, 4 o'clock, p. m. ? 
7. Stockholm, July 1st, 6 o'clock, p.m.? 



CHAPTER III. 

PROBLEMS FOR THE CELESTIAL GLOBE. 

PROBLEM I. 

To find the declination and right ascension of the Sun or a 
Star. 
Rule. — Bring the Sun's place, or the star, to the grad- 
uated side of the brazen meridian, which is numbered 
from the equinoctial towards the poles ; and the degree 
of the meridian, over the Sun's place, or the star, will be 
the declination ; and the number of degrees on the equi- 



ASTRONOMY. Ill 



noctial, between the meridian and the first point of 
Aries, will be the right ascension. 

EXAMPLES. 

1. Find the Sun's declination, and right ascension, on 
the following days : 

June 21st. July 4th. February 1st. 

March 15th. December 2 2d. October 20th. 

January 1st. September 23d. November 23d. 

2. Find the declination and right ascension of — 
Aldebaran. — Answer. Dec, 16° 6' N.; Right Ascension, 66°. 
Arcturus. Bellatrix. Canopus. • Regains. 
Algol. Sirius. Vega. Procyon. 
Capella. Pollux. Menkar. Rastaben. 

PROBLEM II. 

To find the latitude and longitude of a Star. 
Rule. — Screw the quadrant of altitude over the north 
or south pole of the ecliptic, according as the star is in 
north or south latitude ; bring its graduated edge to the 
star : and the number of degrees, on the quadrant, from 
the ecliptic to the star, will be the latitude; and the 
number of degrees, on the ecliptic, from the first point of 
Aries, eastward to the quadrant, will be the longitude. 

EXAMPLES. 

1. Find the latitude and longitude of Aldebaran. — Answer. 
Latitude, 5£° S. ; longitude, 67°. 

2. Required, the latitude and longitude of — 

Markab. Algorab. Scheat. Regulus. 

Rigel. Capella. Mirach. Procyon. 

Arcturus. Sirius. Menkar. Fomalhaut. 



112 ASTRONOMY. 



PROBLEM III. 

The declination and right ascension of a. heavenly body being 
given, to find its place on the globe. 

Rule. — Bring the given degree of right ascension to 
that side of the brazen meridian, Avhich is numbered, 
from the equinoctial towards the poles ; then under the 
given degree of declination, on the meridian, will be the 
star or place required. 

EXAMPLES. 

1. What star has 99-£° of right ascension, and 16£° of south 
declination ? — Answer. Sirius. 

2. "What stars have the following right ascensions and declina- 
tions ? — 

Right Ascension, 205° Declination, 50-J- N. 
150° " 13° N. 

341i° " 30£° S. 

3. When Venus has 3l£ 3 of right ascension, and 12° of north 
declination, what is her place on the globe ? 

4. When Jupiter's right ascension is 212°, and its declination 
20° south, what is its place on the globe ? 

5. When the right ascension of the moon is 350°, and its de- 
clination 12° south, what is its place on the globe ? 

PROBLEM IV. 

The latitude and longitude of a heavenly body being given, 
to find its 'place on the globe. 

Rule. — Elevate the north or south pole, according as 
the given declination is north or south, 66%° ; bring the 
pole of the ecliptic to the meridian, and screw the quad- 



ASTRONOMY* 113 



rant of altitude over it ; bring the graduated edge of the 
quadrant to the given degree of longitude, on the eclip- 
tic; and, under the given degree of declination, on the 
quadrant, will be the star or place required. 



EXAMPLES. 



1. What star has 31° of north latitude, and 201° of longitude ? 
-Answer. Aicturus. 

2. What stars have the following latitudes and longitudes? — 



Latitudes. 


Longitudes. 


Latitudes. 


Longit 


12£° S. 


41i° 


5£°.N. 


67 


16° S. 


86° 


21° S. 


331 


5i° S. 


66i° 


29° JS T . 


299 




PROBLEM 


V. 





The latitude of a place, day of the month, and hour of the 
day, being given, to place the globe so as to represent the 
appearance of the heavens, at that place and time. 

Eule. — Elevate the pole for the latitude of the place ; 
find the Sun's place in the ecliptic, bring it to the me- 
ridian, and set the index to twelve ; if the time be before 
noon, turn the globe eastward; if afternoon, turn it 
westward, till the index points to the given hour ; and 
the surface of the globe will then represent the appear- 
ance of the heavens for the given time and place. 



EXAMPLES. 



Represent the appearance of the heavens at New York, for — 
October 12th, at 10 o'clock, p.m.? 
May 21st, at 9 o'clock, p.m. ? 
December 2 2d, at 3 o'clock, A. m. ? 



114 



ASTRONOMY. 





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ASTK0N03IY. 115 


TABLE II.— THE SECONDARY PLANETS. 

SATELLITES OF JUPITER. 


Name. 


Distance from 
Planet. 


Inclination of Orbit 
to that of Jupiter. 


Revolution. 


Diameter. 


I. . . . 

II. . . . 

III. . . . 

IV. . . . 


Miles. 
265,000 
421,000 
671,000 
1,180,000 


3° 18' 
3° 18' 
3° 14' 
2° 36' 


Days. Hours. 

1 18| 

3 15 

7 4 

16 16i 


Miles. 
2508 
2068 
3377 
2900 


These bodies are supposed to revolve oa axes in the same time as their revolution 
around the planet. 

SATELLITES OF SATURN. 


Name. 


Distance from Planet. 


Inclination of Orbit 
to that of Saturn. 


Revolution. 


1. Mimas . 

2. Enceladus 

3. Tethys . 

4. Dione 

5. Rhea . 

6. Titan . 

7. Hyperion 

8. Japetus . 




Miles. 
119,500 
153,500 
190.000 
243.500 
336,000 
788,000 
1,000,000 
2.297,000 


30° 
30° 
30° 
30° 
30° 
30° 

42 45' 


Days. Hours. 
221 
1 9 

1 2li 

2 18 
4 12i 

15 23 
21 4i 
79 8 


The eighth satellite is supposed to be about as larife as Mars, and the remainder to be 
smaller, according to their respective distances. They are supposed to have a rotation 
on axes, iu the same lime as they revolve around the planet. 

SATELLITES OF URANUS. 


Name. 


Distance from Planet. 


[inclination of Orbit 
to that of Uranus. 


Revolution. 


1 

2 

3 

4 

5 

6 


Miles. 
225,000 
291,000 
340,000 
390,000 
780.000 
1,556,000 


80° 


Days. Hours. 

5 21* 

8 17 

10 23 

13 11 

38 2 

107 17 


Their motion is retrograde, and their orbits are nearly circles. 



GLOSSARY OF ASTRONOMICAL TERMS, 



WITH THEIR DERIVATIONS. 



Altitude — Lat. Altitudo, height. The height of a heavenly body 
above the horizon. 

Amplitude — Lat. Amplitudo, largeness. The distance of a heav- 
enly body from the east or west points of the horizon. 

Annular — Lat. Annulus, a ring. A term applied to an eclipse, in 
which the sun's disc looks like a ring. 

Antipodes — Gr. Anti, against, and podes, feet. Those inhabitants 
of the earth, who live on exactly opposite sides of the earth, 
or feet to feet. 

Antoeci — Gr. Anti, against, and oikos, alwuse. Those whose dwel- 
lings are on opposite sides of the equator, but under the same 
meridian. 

Arctic — Gr. Arktos, a hear. The name of the circle in the vicinity 
of the Constellation of the Bear. 

Antarctic — Gr. Anti, against, and arktos. The circle opposite the 
Arctic circle. 

Aphelion — Gr. Apo, from, and helios, the sun. The point of the 
earth's orbit farthest from the sun. 

Apogee — Gr. Apo and ge, the earth. The point of the moon's 
orbit farthest from the earth. 

Apsis — Gr. Apsis, a joining. The aphelion or perihelion of a plan- 
et's orbit. 

Apsides — Plural of apsis. 

Astronomy — Gr. Astron, a star, and nemo, to classify. The sci- 
ence which classifies and describes the heavenly bodies. 

Asteroids — Gr. Aster, a star, and eido, to resemble. Small planets 
between Mars and Jupiter, at first taken for stars. 



ASTRONOMICAL TERMS. 117 



Atmosphere— Gi\ Atmos, vapor*, and sphsera, a sphere. The body 
of air-, vapor-, &c, which encompasses the earth. 

Azimuth— Arabic* The distance of a body from the north or south 
points of the horizon. 

Asteal— Gr. Aster, a star. Relating to the stars. 

Axis, pi. Axes— Lat, Axis, an axh. The imaginary line on which 
the earth turns. 

Almacantaes— Arabic. Parallels of altitude. 

Binaey — Lat. Binus, two oy ttco. A term applied to systems of 
double stars. 

Culminate — Lat. Culmen, the top. To pass the meridian, because 
then it arrives at its greatest altitude* 

Ceepusctjlum — Lat. Twilight. 

Cusps— Lat. Cuspis, a point* The points of the moon's disc, when 
homed. 

CentbipEtal— Lat. Centrum, a centre, and peto, to seek. The force 
which urges a body towards the centre of motion. 

Centeifugal— Lat. Centrum and fugio, to flee from. The force 
by which a body recedes from the centre of motion. 

Comet — Lat. Coma, hair. A body surrounded by a nebulous ap- 
pearance, resembling hair, 

Conj-itnction — Lat. Con, together, and jungo, to join. The apparent 
meeting of a planet with the sun. 

Constellation— -Lat. Con, together, and stella, a star. A group 
of stars. 

Cardinal — Lat. Cardo, a hinge. The term applied to the four 
principal points of the compass. 

Concenteic — Lat. Con, together, and centrum, a centre. Concen- 
tric circles are those drawn around the same centre. 

Disc — Lat. Discus, a quoit. The circular face of a heavenly body. 
Diametee — Gr. Dia, through, and metron, a measure. The line 

which measures across a circle. 
Digit — Lat. Digitus, a finger. One of the twelve equal divisions 

of the diameter of the disc. 



118 GLOSSARY OF 



Eclipse— Gr, Ekleipsis, a fainting away. The concealment of one 
heavenly body by the interposition of another. 

Ecliptic — From Eclipse^ a great circle in the heavens, so called 
because eclipses only take place when the moon is in its plane. 

Eccentricity — Gr. Ec,from, and centron, a centre. Distance from 
the centre* 

Elongation — Lat. Longus, long. The angular distance of a planet 
from the sun. 

Equator — Lat. iEquo, to divide equally. The great circle which 
divides the earth into northern and southern hemispheres. 

Equinoctial — Lat. iEquus, equal, and noctes, nights. A great cir- 
cle in the heavens, so called, because when the sun is in it, 
every place on the earth has equal days and nights. 

Focus — Lat. Focus, a fire-place. The point within the earth's 
orbit where the sun is situated. (Plural foci.) 

Galaxy — Gr. Galaxias, the milky-icay. Lat. Via Lactea. 
Gibbous — Lat. Gibbus, convex. Term applied to the partial disc of 

the moon, or a planet, when more than half is visible. 
Geocentric — Gr. ge, the earth, and centron, a centre. Seen from 

the earth as a centre. 

Hopjzon — Gr. Horizo, to bound. The circle which bounds our 

vision. 
Heliocentric — Gr. Helios, the sun, and centron, a centre. Seen 

from the sun as a centre. 

Meridian — Lat. Meridies, mid- day. The circle at which the sun 
arrives when it is noon. 

Nadir — Arabic, Nazeer, opposite. The point opposite the zenith. 
Nebula — Lat. Nebula, a cloud. A cloudy appearance among the 

stars. 
Nitrogen — Gr. Nitron, nitre, and gennao, to produce. One of the 

two component gases of air. 
Nodes— Lat. Nodus, a knot. The points at which the orbit of a 

planet intersects the ecliptic, or plane of the earth's orbit. 



ASTRONOMICAL TERMS. 119 



Nucleus — Lat. Nucleus, a kernel. The bright and seemingly solid 

part of a comet. 
Nutation — Lat. Nutation, a nodding. A vibratory motion of the 

earth's axis. 

Oebit — Lat. Orbis, a circle. The path of a heavenly body. 

Oxygex — Gr. Oxus, acid, and gennao, to produce, One of the com- 
ponent gases of the atmosphere. 

Occultatiox — Lat. Occultatio, a hiding. The concealment of a 
heavenly body by the moon. 

Octant — Lat. Octo, eight. The eighth part of a circle. 

PaeallAx — Gr. Parallaxis, change. The difference in the apparent 
position of a heavenly body, from a change of place in the 
spectator. 

Peeiheliox— Gr. Peri, near, and helios, the sun. The point of a 
planet's orbit nearest the sun. 

Peeigee — Gr. Peri, near, and ge, the earth. The point of the 
moon's orbit nearest the earth. 

Peeioeci— ~Gr. Peri, around, and oikeo, to dioell. Those who dwell 
under the same parallel, but in opposite meridians. 

Pexumbea— Lat. Pene, almost, and umbra, a shadow. An imper- 
fect shadow. 

Phase — Gr. Phasis, an appearance. The portion of a body's disc 
visible. 

Plaxet — Gr. Planetes, a wanderer. An opaque body attending the 
sun, so called because, Unlike the fixed stars, planets change 
their apparent relative positions, 

Quadeatuee — Lat. Quadra, a square. The position of a body 

when its angular distance from the sun is 90 degrees, or a 

right angle. 
Quadeaxt — Lat. Quadrans, the fourth part. The fourth part of a 

circle. 
Quaetile- — Lat. Quartus, fourth. The aspect of two planets 90 

degrees from each other. 



120 GLOSSARY OF 



RETKOGRADE-^-Lat. Retrogradus, bach.cards-. The apparent back- 
ward motion of the planets. 

Refraction-* Lat. Refract as, broken. The deviation or breaking 
of the rays of light. 

Radius- 5 — Lat. Radius, a ray, Plural-, radii. Lines drawn from the 
centre of a circle to every part of the circumference, as rays 
proceed from the sun. 

Satellite-— -Lat. Sate-lles, a guard. An attendant body of a pri* 
mary planet, 

Sidereal— Lat. Sidus, a star. Relating to the stars. 

Solar — Lat. Sol, the sun. Relating to the sun. 

Solstice-— Lat. Sol, the sUt^ and sto, to stand. The point of the 
ecliptic, at which the sun stands, with respect to decli- 
nation. 

Sextant**- Lat. Sextus. sixth. The sixth part of a circle. 

Stellar— -Lat. Stella, a star. Relating to the stars. 

Sextile — Lat. Sextus, sixth. The aspect of two planets 60 de- 
grees from each other* 

Secondary— Lat. Secundus, second. A great circle perpendicular 
to any other, or a term applied to the satellites. 

Synodical — Gi\ Syn, together, and odos^ a pathitay. The Synod- 
ical revolution is the time between two conjunctions. 

Syzygies— -Gr. Syzygia, conjunction. The conjunction and opposi- 
tion of the moon, 

Telescope — Gr. Tele, at «• distance, and scopeo, to see, An instru- 
ment for viewing objects at a distance. 

Terminator— Lat. Terminus, a boundary. The line which divides 
the enlightened from the dark part of the moon. 

Transit— Lat. Transitus, a passage across. The passage of a planet 
across the sun's disc. 

Trine — Lat. Trinus, three. The aspect of two planets 120 degrees 
from each other. 

Tropics— Gr. Trope, return. The small circles which limit the 
sun's declination, so that, when it reaches one, it returns to 
the other. 



ASTRONOMICAL TERMS, 121 



Umbra — .Lat, Umbra, a shadow* The conical shadow of the earth 
or moon, 

YECTOE-^-Lat. Vector, one who carries. The radius-rector is a line 
drawn from the sun, to any point of the orbit of a planet, by 
which the planet appears to be carried around the sun. 

Vertical — Lat. Vertex, the top. A term applied to the sun when 
directly overhead. 

Zextth— Arabic. The peint cverhead. 

Zodiac — Gr. Zodiakos, of animals. The belt which contains the 
twelve constellations lying on the ecliptic, represented by ani- 
mals. 

.Zo^ t e— Gr, Zone, a gird.U. A division of the earth's surface. 



QUESTIONS FOR REVIEW. 



1. What is Astronomy ? 

2. Of what bodies does it treat ? 

3. Into what two classes may the heavenly bodies be divided? 

4. "What is a luminous body ? 

5. What is an opaque body ? 

6. What is the Solar System ': 

7. What is a planet ? 

8. How many kinds of planets are there ? 

9. What is a primary planet ? 

10. What is a secondary planet ? 

11. Name the primary planets. 

12. Mention the diameter of each. 

13. Mention the distance of each from the sun, 

14. What is the time of the annual revolution of each ? 

15. What is the time of the diurnal rotation of each % 
26. How are the satellites distributed ? 

17. What are Asteroids ? 

18. Mention their number and names, 

19. Which are the inferior planets? 

20. Which are the superior planets ? 

21. Why are they so called ? 

22. What is elongation ? 

23. What is inferior conjunction? 

24. What is superior conjunction ? 

25. What is opposition ? 

26. What is quadrature ? 

27. What is the disc of a heavenly body ? 

28. What is a digit? 

29. What is the orbit of a planet? 



QUESTIONS FOR REVIEW. 123 

30. "What is the shape of the planets' orbits ? 

31. Repeat Kepler's laws. 

32. What is the radius-vector of a planet's orbit ? 

33. What is the eccentricity of a planet's orbit ? 

34. What is centripetal force ? 

35. What is centrifugal force ? 

36. What is the aphelion? 

37. What is the perihelion ? 

38. What is the apsis line? 

39. What is the apogee ? 

40. What is the perigee ? 

41. What are the mean and true places of a planet ? 

42. Where is the velocity of a planet the greatest ? 

43. Where is it the least? 

44. What are the nodes ? 

45. What is the ascending node ? 

46. What is the descending node ? 

47. What is the axis of the earth ? 

48. Mention the principal great circles on the globe. 

49. Define each. 

50. What is latitude on the earth ? 

51. What is latitude in the heavens ? 

52. What is declination ? 

53. What is longitude on the earth ? 

54. What is longitude in the heavens ? 

55. What is right ascension ? 

56. Mention the principal small circles on the globe. 

57. Define each. 

58. What is the equinoctial coiure ? 

59. What is the solstitial coiure ? 

60. What are zones ? 

61. Tell the position and width of each. 

62. What is the horizon ? 

63. What is the sensible horizon ? 

64. What is the rational horizon ? 

65. What are the poles of the horizon? 

66. Define each. 



124 QUESTIONS FOR REVIEW. 

67. What is the altitude of a heavenly body ? 

68. What is the azimuth ? 

69. What are the vertical circles? 

70. What is the prime vertical ? 

71. What is amplitude ? 

72. What is polar distance ? 

73. When has a place a vertical sun ? 

74. Where must a place be situated, to have a vertical sun ? 

75. What is the circle of perpetual apparition ? 

76. What is the circle of perpetual occultation ? 

77. How many positions has the sphere ? 

78. Define each. 

79. What are the Antipodes ? — Antoeci ? — Perioeci ? 

80. What are the equinoctial points ? 

81. What are the solstitial points ? 

82. What are the signs of each ? 

83. What is the zodiac ? 

84. Repeat the signs of the zodiac. 

85. Tell when the sun enters each. 

86. What causes day and night? 

87. How is the change of the seasons produced? 

88. When are the days and nights everywhere equal ? 

89. When is it longest day in the northern hemisphere ? 

90. When, in the southern hemisphere ? 

91. When have places, in the north frigid zone, constant day ? 

92. What is the sun supposed to be? 

93. What is its diameter ? 

94. How many, and what, revolutions has it ? 

95. How was the rotation on its axis discovered ? 

96. "What are the spots, on the sun, supposed to be ? 

97. What is the velocity of light ? 

98. What is the supposed nature of light ? 

99. What is the position of the sun's axis ? 

100. Which planet is nearest the sun? 

101. In what respects is it remarkable ? 

102. Mention the greatest elongation of Mercury. 

103. When is Yenus called the morning star ? 



QUESTIONS FOR REVIEW. 125 

104. When, the evening star? 

105. What seasons has Venus? 

106. What are the transits of Mercury and Venus ? 

107. What does a transit prove ? 

108. What is the shape of the earth ? 

109. State its equatorial and polar diameter. 

110. What proofs have we that it is spherical? 

111. When does it pass its aphelion? 

112. When its perihelion? 

113. State the proofs of its revolving on its axis. 

114. What gives it the shape of an oblate spheroid ? 

115. What is its density \ 

116. Mention the density of the planets. 

117. By what is the earth attended? 

118. By what is it surrounded ? 

119. Of what does the atmosphere consist? 

120. Of what is air composed ? 

121. What are clouds ?— Wind ? 

122. How is wind produced ? 

123. What are the trade winds ? 

124. How are they caused ? 

125. What are land and sea breezes ? 

126. How is rain caused ? — Snow ? — Hail ? 

127. What are fogs and mists ? 

128. How are they caused? 

129. What is dew? 

130. Mention some of the uses of the atmosphere? 

131. What is the moon? 

132. Mention its diameter, and distance from the earth. 

133. How many revolutions has it ? 

134. What is the time of each ? 

135. What is a synodical month ? 

136. Why is it longer than a complete revolution? 

137. Does the moon rise at the same hour, always ? 

138. Why does it rise later ? 

139. What is harvest moon ? 

140. Explain its cause. 



126 QUESTIONS FOR REVIEW. 

141. What are the phases of the moon ? 

142. When is it new moon ? 

143. When is it full moon ? 

144. When is it first quarter? — Last quarter? 

145. What is the appearance of the moon in each? 

146. When 3s the moon horned ? — When gibbous ? 

147. Can we see the entire surface of the moon ? 

148. Which is the fourth planet from the sun ? 

149. In what respects is its figure remarkable ? - 

150. What phases does it present ? 

151. Why is it never horned ? 

152. What is the magnitude of Jupiter, compared with the earth ? 

153. What seasons has it? 

154. By what is Saturn encompassed? 

155. State the dimensions and distances of the rings. 

156. Which is the remotest planet known? 

157. State the time and manner of its discovery. 

158. How are the asteroids distinguished from the other planets? 

159. What is their average distance from the sim? 

160. What is the time of their annual revolution ? 

161. What apparent revolutions have the heavenly bodies ? 

162. How are they caused? 

163. How many apparent motions have the planets ? 

164. When is a planet's motion said to be direct? 

165. When, said to be retrograde ? 

106. When is a planet said to be stationary? 

167. How are these appearances caused? 

168. When is the motion of an inferior planet retrograde ? 

169. When is it direct? 

170. When does it appear stationary ? 

171. Describe the apparent motions of a superior planet. 

172. What is an eclipse? 

173. Which are the principal eclipses? 

174. What is a solar eclipse? 

175. How is it caused \ 

176. What is a lunar eclipse, and how is it caused ? 

177. Of how many kinds are eclipses ? 



QUESTIONS FOR REVIEW. 127 

178. What is a total eclipse ? 

179. What is a partial eclipse? 

180. What is an annular eclipse? 

181. When does it happen? 

182. What is the ecliptic limit? 

183. What is the extent of the solar ecliptic limit ? 

184. What is the extent of the lunar ecliptie limit ? 

185. What is the penumbra ? 

186. What is the length of the earth's shadow? 

187. What is its breadth, where it eclipses the moon? 
18-8. What is the length of the moon's shadow ? 

189. What is its diameter, where it intersects the earth ? 

190. How many eclipses may happen in a year ? 

191. What is occultation? 

192. What are tides ? 

193. How are they divided ? 

194. What is flood tide ?— Ebb tide ? 

195. How often do they happen? 

196. What is spring tide ? — Neap tide ? m 

197. When do they occur? 

198. By what are tides occasioned? 

199. Which has the greatest effect, the sun or moon? 

200. Why does the moon produce the highest tides ? 

201. How is spring tide caused ? 

202. How is neap tide caused ? 

203. What are primitive tides? 

204. What are derivative tides ? - 

205. Where do the highest tides occur ? 

206. What is the average height for the whole globe ? 

207. Do the tides always rise at the same hour ? 

208. Why not? 

209. Does the tide rise immediately the moon passes the me- 
ridian ? 

210. Why not? 

211. How much behind the moon are the tides, in the ocean ? 

212. How much at New York? 

213. Does the tide rise as high, daring the night, as during the day? 



128 QUESTIONS FOR REVIEW. 

214. What is parallax? 

215. What is the apparent place of a heavenly body? 

216. What is the true place of a heavenly body I 

217. What is diurnal parallax ? 

218. What is horizontal parallax ? 

219. Where is diurnal parallax the greatest 1 

220. Where is it the least ? 

221. How does it affect the apparent place of a "body? 

222. What is annual parallax ? 

223. What bodies have annual parallax 1 

224. What is the parallax of the nearest fixed star ? 

225. What is refraction ? 

226. Where is it the greatest 2 

227. Where the least ? 

228. How great is it, when the body is in the horizon ? 

229. How does it affect the apparent place of a body ? 

230. How does it affect the sun, at its rising and setting ? 

231. What is twilight? 

232. How is it caused ? 

233. How far below the horizon is the sun,, when it commences 
and ends ? 

234. At Avhat parts of the earth is it shortest ? 

235. At what parts, longest ? 

236. What is time? 

237. How is it measured ? 

238. How many kinds of days are there ? 

239. What is a solar day ? 

240. What is a sidereal day ? 

241. Which is the longer, and by how much? 

242. Why is it longer \ 

243. What is apparent time? 

244. What is mean time? 

245. What is the equation of time? 
246.. When is it the greatest? 

247. When is it nothing? 

248. Explain the causes of the equation of time. 

249. What is the precession of the equinoxes ? 



QUESTIONS FOR REVIEW. 129 



250. What is the amount of precession annually ? 

251. In what time do the equinoxes complete a revolution? 

252. Explain the cause of precession. 

253. What is a tropical year? 

254. What is a sidereal year ? 

255. Which is the longer? — Why? 

256. What motion has the line of apsides? 

257. When does it complete a revolution? 

258. How much does the longitude of the perihelion, increase 
annually ? 

259. What are comets ? 

260. Of what parts, does a comet consist? 

261. Define each. 

262. How do comets revolve? 

263. What are they supposed to be ? 

264. What are the fixed stars ? 

265. What are they believed to be ? 

266. What is their supposed size ? 

267. What is the distance of the nearest ? 

268. What are variable stars? — How accounted for? 

269. What are temporary stars ? — How accounted for ? 

270. What are nebulous stars ? — Multiple stars ? 

271. What are double stars, and binary systems ? 

272. How many have been discovered ? 

273. What is the galaxy or milky- way ? 

274. What is a cluster? 

275. What are nebulae ? 

276. How are they divided ? 

277. Define each. 

278. Of what is the universe supposed to consist ? 

279. What is a constellation? 

280. How many are there ? 

281. How are they divided ? 

282. Explain the position of each. 

283. Do the signs and constellations of the zodiac correspond ? 

284. When did they occupy the same places ? 

285. How are the stars classified ? 



6* 



130 QUESTIONS FOR REVIEW. 

286. "What are telescopic stars ? 

287. "What does the terrestrial globe represent ? 

288. What does the celestial globe represent? 

289. What is the brazen meridian ? 

290. How is it numbered ? 

291. What is the wooden horizon ? 

292. What does it represent ? 

293. What is the hour circle? 

294. When are meridians called hour circles? 

295. What is the quadrant of altitude ? 
290. For what is it used? 

297. What is the mariner's compass ? 

298. Mention the cardinal points of the horizon. 

299. What is the angle of position of two places? 

300. What are rhumbs ? 

301. What is a rhumb line? 



NEWMAN & IVISOX'S PUBLICATION'S. 



SANDERS' SERIES 



OF 

SCHOOL READERS, 

CONSISTING OF 

SANDERS' PRIMARY SCHOOL PRIMER; 6 cts. 
SANDERS' PICTORIAL PRIMER; 12* cts. 
SANDERS' SPELLING BOOK, 168 pages. 12§ cts. 
SANDERS' SCHOOL READER, 1st Book; 120 pages. i2| 
SANDERS' SCHOOL READER, 2d Book; 180 « is 
SANDERS' SCHOOL READER, 3d Book; 250 « 37§ 
SANDERS' SCHOOL READER, 4th Book; 364 « 62 
SANDERS' SCHOOL READER, 5th Book: 456 " 75 

These books constitute the most valuable series ever published — a fact 
fully evinced by the generous patronage which they have received from 
the Friends of Education throughout the country. More than two mil- 
lions have been sold, and the demand is increasing. Their leading ad- 
•antages are as follows: 

1st. The child is taught to read by the use of intelligible words only 
-'beginning with the least, as those of two letters, and gradually advan- 
cing to those of greater length. 

2d. All the words in the first book, or Primer, are learned by the 
scholar in the spelling lessons, before they meet with them in the reading 
lessons. Also, the difficult words of each reading lesson, in all the Read- 
ers, are previously formed into spelling lessons. 

3d. In the 3d and 4th Readers, the difficult words are defined in a 
general and literal sense. 

4th. The Primary books contain more lessons of easy readmg than other 
works — there being about ninety pages made up of monos^lables. 

5th. The progression from one book to another, is more regular, grad- 
ual, and philosophical than usually found. 

6th. The lessons are adapted to interest as well as instruct. 

7th. The practical and judicious use of pictures is calculated to assist, 
and not retard, the efforts of the teacher. * 

8th. The practical instructions in the Rhetorical principles of read- 
ing and speaking, contained in the 4th Reader, constitute a distinguishing 
characteristic of the work. 

9th At the end of each lesson for reading, questions are asked, with 
reference to the proper inflections, emphasis, &c, which should be adopted 
in reading the lesson with propriety. 

10th. In connection with the questions, are references to the instruc- 
tions in other parts of the work. 

11th. The print is large and distinct, gradually diminishing from the 



JCEWMAX <k IVISOX'S PUBLICATIONS. 



large print of the Primer to that of the ordinary size, contained in tbe 4th 
Reader. 

12th. A greater variety, hoth in style and subject, is found in this 
series than is usual in hooks of the kind. 

13th. The Spelling ami Pronxnu at ion throughout the series are uni- 
formly in accordance with those of Dr. Webster. 

14th. The instructions in the sounds and power of letters, as well 
as the " General Rules for Spelling," are more clearly presented in 
" Sanders' Spelling Book," than any other work of the kind. 



The Convention of State and County Superintendents of Schools in 
Vermont, held pursuant to adjournment in the State House, Montpclier, 
Oct. 14, 1846, unanimously recommended Sanders' Series of School 
Books, consisting of Sanders' Spelling Book, Pictorial or Primary Scho-1 
Primer, and Sanders' Readers, Nos. 1, 2, 3, and 4, for the uniform adop- 
tion in the Common Schools of the State. Of this Convention Hon. 
D. M. Camp was President. 



From, A. S. Lcn: ell, Principal of City High School, yiiddletovrn, Conn. 

Having carefully examined Sanders' Series of School Books, I most 
cheerfully recommend their general adoption, as I believe them to excel in 
several respects any series at present before the public. 

July, lo45. A. S. Lovell. 



Extract from a letter from Rev. Stephen Marilr.dale and Dr. Sathaniel 
Ives, the County Committee on Reading Books for Rutland Co., 17. 

To Mr. C. W. Sanders :— 

Sir — Comparatively it is but light praise to say that the lesMttS 
are admirably arranged to give tbe necessary healthful exercise to the 
opening and expanding intellect of the pupil; gradually increasing from 
the simpler forms of ideas to those that aie complex, and by easy grada- 
tions, progressing to even the initiatory forms of profound ratiocina- 
tion, all in a clear, pure, and at times even an elevated style, that cannot 
fail to be of essential service to pupils usin^ these books. The grand 
crowning excellence of this series, is the rich vein of sound philosophy 
and truly Christian morality, that pervades the whole; uncontaminatrd 
by even an appearance of that sickly pseudo imitation of Christianity , with 
which we have found some works of this class to be unhappily replete; 
and which, under the specious mask of an outward respect lor the princi- 
ples of our holy religion, artfully inculcate the idea that man, unaided by 
divine grace, is perfectly able to render himself all thai God requires; and 
that, as a necessary consequence, the Christian religion, being in reality 
unnecessary, is, in truth, but a useless and burdensome form of supersti- 
tion. 

In conclusion, allow us to assure you that it will afford us unalloyed 
satisfaction, to learn that the public appreciate your works in a decree 
commensurate with thi ir merits. 

We are, sir, respectfully and truly yours, 

Stephen Martindale, 
Nathaniel J yes. 
Wallingford, Rutland Co., Vt., September 18, 184G. 

e 



NEWMAN & IYISON'S PUBLICATIONS. 



SANDERS' SERIES OF READERS. 



From the Committee on the Subject of Education, appointed by the Senate of the State 
of Illinois. 

We have compared Sanders' Series of Reading Books -with the Eclectic Series 
of Prof. McGuffey, and we have a very decided preference for those of Mr. Sanders, and 
recommend that they be adopted uniformly hy the schools of the State of Illinois. 
Farther, we have exa.x ned Day and Thomson's Arithmetical Series, Willson's His- 
tories, and Gray's Chemistry, ami find them superior to any other works of the kind, 
with which we are acquainted, and think that the interests of education woidd be ad 
vanced by their introduction generally into the Common and High Schools of the State, 

NEWTON CLOUD, ) 

JOSEPH GILLESPIE, | Committee of Senate 
City of Sprinrfield, WILLIAM TTCHNOR, V on the 

Jan. 1G, 18*49. W. B. PLATS, Subject of Education. 

r. C. HARDY, J 

.in extract from a communication to the Board of Trustees and Visitors of the Common 
Schools, Cincinnati, Ohio, signed by the SEVENTY TEACHERS of that city. 

After examining such reading books as we have had access to, we are of opinion that 
the Series of Readers, known as Sanders' Series, have merits which highly recommend 
them to your favorable notice — some of which are peculiar. We believe that the im- 
portant object of gradually progressive lessons, both in subjects and language, is mora 
nearly attained in that series than in anv other with which we are acquainted. 

Signed by SEVENTY TEACHERS, Cincinnati. 

Extract from a Petition, presented to the Board of Education, by the Principals of trie 
Public Schools for the city of Rochester. 

"We, the undersigned, teachers in the Public Schools in the city, believing as we do, 
that some changes in our text-books, upon certain conditions, would give a healthful 
stimulus, facilitating our onward progress, therefore unite, earnestly soliciting the Hon. 
Board of Education to substitute Sanders' Spelling Book and Series of Readers 
for use in our schools, for those now in use. 



C. MESERVE, Princ 


ins! 


No. 


1. 


* C. W. COLYER, 


in No. 


14. 


M. DOUGLASS. " 




No. 


9. 


W. OGDEN, 


" No. 


6. 


J. R. VOSBURGH, « 




No. 


13. 


E. S. TREAT, 


" No. 


5. 


LEWIS BIXBY, " 




No. 


14. 


A. W. FISHER, 


" No. 


10. 


DONALD G. FRASER, 




No. 


15. 


• WM. DALLIS, 


" No. 


3. 


WM. WATSON, " 




No. 


11. 


A. N. MERRIMAN, 


" No. 


11. 



From Principals of Public Schools in the city of Buffalo. 

We have examined Sanders' Fifth Reader, edited by C. W. Sanders of New York, 
and find the selections appropriate, and their moral tone of a highly elevated character 
The work seems admirably calculated to make easy, natural, and intellectual readers. 

A. L. BINGHAM, Prill, of Public School, No. 11. 

SAMUEL SLADE, Prin. of Public School, No. 3. 

D. P. LEE, Principal of Public School. No. 7. 

June 14, 1843. E. F. COOK, 3d Department, Public School, No. 10. 

From A. S. Lovcll, Principal of City High School, Middletown, Conn. 

Having carefully examined Sanders' Series of School Books, I most cheerfully r«v 
commend their general adoption, as I believe them to excel in several respects any seriea 
at present before the publi.8. 

JW«,1845. * 4.S.1.0VELU 

1 



NEWMAN & IVISON'S PUBLICATIONS. 



DAY AND THOMSON'S SERIES : 

BEING A NSW AND COMPLETE COURSE OP MATHEMATICS FOR SCHOOLS ANO 

ACADEMIES, BY JEREMIAH DAY, LL.D., LATE PRESIDENT OF YAI E 

COLLEGE, AND JAMES B. THOMSON, A.M. 

The following ii a summary of the General Plan :— 

1. The series is practical in t?ie fullest sense of the term. 

2. Unity of design runs through the whole series ; while it embraces all the subject* 
necessary for a thorough mathematical education. 

3. Great care is taken never to anticipate a principle, and never to use one principle 
in the explanation of another, until it has itself been esjilained or demonstrated. 

4. It abounds in examples for practice. Without much practice it is impossible to 
make the application of the rules well understood and remembered. 

6. The definitions are designed to be simple and exact, yet free from redundancies of 
expression. 

6. The arrangement of subjects is systematic and natural. 

7. The mode of reasoning is inductive, clear, and logical. 

8. The rules are plain and brief. 

9. Every principle is carefully analyzed, and the reason of the rules fully explained. 

10. One principle is explained at a time, and a sufficient number of examples is given 
under it, to make its application well understood. 

11. When a principle or term has been defined in one part of the series, if that prin- 
ciple or term occurs in a different part, the same definition is used. 

12. The explanations are simple, direct, and clear; and the examples for illustration, are 
practical and apposite. 

NO. 1.— MENTAL ARITHMETIC, 

Or First Lessons in"ftumb*r3 for Children, by James B. Thomson, A. M. New edi- 
tion, revised and enlarged. ISrao, 108 pages, half bound. 12^ cents. 

This work commences with the simplest combinations of numbers, and gradually ad- 
vances, as the mind of the learner expands, and is prepared to comprehend more difficult 
questions. 

"Thomson's ' Menta. Arithmetic' I think is much the best I have ever examined. It 
seems to me to be the very thing needed by the youthful mind, when first entering upon 
the science of numbers."— James M'Giffert, A M, Sup't Com. Schools, Greenport, N.Y., 
late Prof. Mathematics-, city of New York. 

" I take pleasure in stating that the plan and arrangement of the work are superior to" 
any with which lam acquainted The directions tor using that almost indispensable 
piece of apparatus, the Numercal Frame, and the notes for the aid of the young teacher, 
contribute greally to its usefulness and value, and are sufficient to commend the work to 
every teacher of Common Schools.'" — IV. F. Phelps, Esq., Principal of the Experimental 
School attached to the New York State Normal School. 

NO. ^.—PRACTICAL ARITHMETIC, 

Uniting the Inductive with the Synthetic modes of Instruction, also illustrating the 
principles of Cancelation, for Schools and Academies. By James B. Thomsx.* , A.M 
New edition, revised and enlarged. 12mo, 342 pages, half bound. 38 cents. 

Tie design of this work is to lead the pupil to a knowledge of Arithmetic by indvctlrm, 
to analyze every rrinciple separately, and to make him thoroughly acquainted with tine 
reason of every operation which he is required to perform, it abounds in examples, and 
is eminently practical. 

" Thomson's Practical Arithmetic will commend itself to Teachers for the clearness and 
precision with which its rules and principles are stated, for the number nnd varie'y of ex- 
amples it furnishes as exercises for the pupil, and especially for the care which the author 
has taken to present appropriate suggestions and observations wherever they are needed, 
to clear up any difficulties that are likely to embarrass the learner. In recommending tha 
work as a class-book for pupils, it is not unimportant to state, that the author has him- 



12 



NEWMAN & IVISOX'S PUBLICATIONS. 

self had much experience in the business of instruction, and has thus had occasion to 
know where there was room for improvement in the elementary treatises in common use. 
"Without such experience, no one can be qualified to prenare a class-book for schools. — 
A D. Stanley, A M., Prof of Mathematics, Yale College. 

" I am particularly pleased with the practical character of your Practical Arithmetic, the 
systematic and natural arrangements of its parts, the exactness of the definiticns, tho 
Clearness wi f h which the principles axe explained and illustrated, and the concise, yet ex- 
plicit language with which tho rules are stated. You have done a good service by :e- 
moving from the tables nf "Weights and Measures all denominations out of use, and by in- 
troducing those adopted by the General Government. The work, in fine, is well adapted 
to the purposes of instruction"— Samuel Green, A.M .. Principal of the Philips' Grammar 
School, Boston, Mass. 

" New York, June. 1847. 

" The undersigned. Commissioners and Inspectors of Common Schools of the Thir- 
teenth Ward, take great pleasure in stating that after a careful and prolonged examina- 
tion into the relative merits of a great number of Arithmetics, presented for their consid- 
■ f eration, (which number embrace all the most popular ones in present use,) have unani- -. 
mously adopted Day and Thomsons Menial, and Practical Arithmetics for use in Ward 
School, No 19., recently organized and opened under their supervision. These books being 
considered lor perspicuity of arrangement, and adaptation to the comprehension of the 
pupil, with, or in the absence of a teacher, preferable to any books on the same subject, 
which have come under their consideration."— William A. Waiters, William Tyler 
Anderson, Charles D. Field. {One vacancy in the Board ) 

NO. 3.—KEY TO PRACTICAL ARITHMETIC 

Containing tke Answers to all the Examples ; with many suggestions, aEd the solu- 
tion of the most difficult questions. 12mo. 38 cents. 

*** The Mental Arithmetic has been published about a year, and the Practical Arith- 
metic about a year and a half. Thoy have been adopted by the State of Rhode Island ; 
Ontario, Livingston, Onondaga, Greene, and Oswego counties, N. Y. ; the City of New 
Haven, Connecticut : Springfield, Mass ; Buffalo, N. Y , and a large number of Acade- 
mies and Schools. No school books have given more entire satisfaction than these Arith- 
metics. Their success, it is believed, has been unparalleled. 

KO. £.— HIGHER ARITHMETIC, 

Or the Theory and Application of Numbers, combining the Analytic and Synthetie 
modes of Instruction, adapted to Scientific and Commercial purposes. By James B. 
Thomson, AM. Large 12rno, full bound in leather. 75 cents. Just published. 

This work is complete in itself, commencing with the fundamental rules, and 
extending to the highest department of the Science. It is constructed on ths 
principlf , that in Arithmetic, " there is a place for everything, and that every- 
thing should be in its proper place ;" that there is treason for every operation, and 
the learner should understand it. It is designed for advanced classes in Schools 
and Academies, who are preparing for the important office of Teaching^ or extended 
mercantile pursuits. 

NO. 5.=KEY TO THE HIGHER ARITHMETIC; 

Containing the Answers to all the Examples, with many suggestions, &c 

NO, 6.—ELEMENTS OF ALGEBRA, 

Being a School Edition of Day's Large Algebra. 7c cents. (Durrie & Peck ) 

This work is designed to be an easy and lucid transition from the study of Arithmetic 
to the higher branches of Mathematics. It is highly recommended by Prof. Olmsted, and 
the Faculty of Yale College ; also by Bishop Potter, Presidents Nott, Wayland, Hopkins 
North, and others. 

NO. 3>~KEY TO THE ELEMENTS OF ALGEBRA. 

Containing all the Answers, with numerous suggestions. 75 cents. (Durrie & Peck.) 

NO. 8.— ELEMENTS OF GEOMETRY, j 

Being an Abridgement of Legendre*s Geometry, with Practical Notes and Illustra- 
tions. Bound in leather. 75 cents. (Durrie & Peck.) 

This work has received the warmest approbation of many ef the most eminent Teach- 
trs and practical Educators 

NO. 9.— ELEMENTS OF TRIGONOMETRY, MENSURATION, AND 

LOGARITHMS. 

NO. 10.—ELEMENTS OF SURVEYING', 

Adapted both to the wants of tlw Learner and the Practical Surveyor. (Pub. sooo.) 

13 



KEWMAK & IVISON'S PUBLICATIONS. 



DAY AND THOMSON'S ARITHMETICS. 



On the subject of the Merits of these works, the publishers will say nothing, but 
merely submit the following reasons in favor ot their adoption. — condensed from th« 
expressed opinions of teachers, superintendents, and committees, who have examined 
liiem. 

I.-MENTAL ARITHMETIC. 

Among the numerous reasons given for the adoption of this work are the following:— 

1. M That it begins and ends in just the right places and in just fr.e' right way." 

2. "That it equally avoids the childishness and puerility of some works on the sub* 
Ject, and the complication and difficulty of others." 

3. " That th j lessons gradua'ly increase in difficulty, and in a manner happily adapted 
to the expanding minds of children, from six to ten years of age." 

4. "That these lessons are rendered interesting to the young, by the great variety of 
persons, incidents and circumstances embodied in them — strikingly contrasting with 
that repulsive monotony, where the same name and the same object occur throughout a 
whole lesson." 

5. '-That pictures and marks are excluded from the book, and their places sup- 
plied by the Numerical Frame, for the use of which ample instructions are given." 

6. "That the lessons are so arranged that the reo-ular increase of numbers is con- 
tinually broken up, and thus the solution of each question requires thought and fur- 
nishes direct mental exercise for the pupil." 

7. "That in the progress of the book, the first example involving a new principle 
is carefully analyzed, and affords a model of reasoning for the solution of aU similar 
questions." 

8. "That after the pupil has become priGt : r.i'ln acantinted with the princip'es of a 
mle, and is able to solve examples under it with facility, the operation is then d-jined, 
and its more prominent terms brieily explained." 

II -FRACTICAL ARITHMETIC. 

Among the reasons given for preferring this work we select the following: — 

1. "That the arrangement of the subjec's is consecutive, systematic, and natural." 

2. "That the language employed in the definitions and rules is peculiarly appropriate, 
concise, and clear." 

3. "That great car9 is taken never to anticipate a principle, and that no principle is 
used in the explanation of another, until it has itself been explained or demonstrated." 

4. "That each principle is explained separately, and carefully analyzed— the why and 
the wherefore of each step in the process are e'e irly an I explicitly given." 

5. "That the examples are numerous and diver.-uiied : their arrangement is gradual 
and progressive ; and the work is calculated to impress upon th9 pupil's mind an abid- 
ing knowledge of the subj""/." 

o\ "That the notes, observations, a->d suggestions, contained in the work, form an 
admirable system of instruction for the student, and afford important aid to the teacher." - 

7. "That .Mental Arithmetic, instead of being pursued to a tedious and unprofitable 
length independent of written Arithmetic, is here immediately connected with it, and ia 
made introductory to every department of the subject. Thus mental operations are 
connected with the use of the slate throughout the coarse." 

8. "That it is strictly an American Book* — arranged in exact accordance with the 
existing state and national laws, and the practice of business men." 

9. "That the old, obsolete an I use 1 ess forms of arithmetical operations are rejected, 
and their places supplied by valuable improvements," 

10. "That instead of giving the pupil a rale and requiring him to understand it be- 
fore he i:s furnished with an example, this work first gives an example, Lieu tells the 
pupil how to do it, and why he did it, and then gives a abort, clear and comprehensive 
rule for it." 

1 1. " That in nearly every article, something is gained in the mode of presenting the 
subject, perspicuity and precision being remarkable throughout." 

12. " That in studying this book, the pupil's mind is thoroughly and actively exer- 
cised ; not in seeking for hours to comprehend the meaning of obscure and knotty pro- 
positions—the unraveling of which has no more practical bearing than the solution of 
a riddle or conundrum, but is exercised upon practical and useful principles, which he 
can understand and apply as occasions for their use arise in after life." 

* Thomson's Practical Arithmetic has the honor of being the first school book wh'ch 
published the standard units of Weights and iieasures adopted by the Government of 
the United States. 

14 



NEWMAN & IVISON'S PUBLICATIONS. 

BUSH'S NOTES ON THE OLD TESTAMENT. 

CRITICAL, EXEGETICAL, AND PRACTICAL. 



NEWMAN & IVISON, by a recent arrangement with the author, have become the 
sole publishers of this valuable series of Notes, which now comprises seven volume?, 
and covers the entire Pentateuch, with the exception of Numbers and Deuteronomy, to 
wit: 

GENESIS 2 vols. $1 75 

EXODUS 2 vols. 1 50 

LEVITICUS lvol. 75 

JOSHUA 1 vol. 75 

JUDGES., 1 vol. 75 

The two last have been for some time out of print. They are now published in uni- 
form style with the others, and we are prepared to furnish the work to the trade in any 
quantities. 

The character of Prof. BUSH'S Notes has become amply established, and the grow- 
ing demand from year to year makes assurance doubly sure, that as a help to biblical 
instruction in that department of the Scriptures which they occupy, they are truly inval- 
uable. During the twelve years that the work has been before the public, from thirty 
to forty thousand copies have been sold, and from present indications this number is 
destined to be vastly increased. For a clear and accurate analysis of the force of origi- 
nal terms— putting the English reader almost upon a par with the Hebrew scholar — for 
a satisfactory solution of difficulties— for felicitous citation of parallel passages — and for 
a vein of pertinent and impressive practical remarks— it would not be easy to name any 
work in the language of superior merits. The testimonials received in great numbers 
from pastors and bible-class teachers in all sections of the country, put its value in these 
respects beyond question. 

Another striking feature of these Notes is the pictorial illustrations by which they are 
distinguished, and which throw such important light upon many subjects of antiquity, 
that urgently require it. The whole Levitical service — the Tabernacle and all its ap- 
pendages — receive from this source a fulness and distinctness of elucidation which 
were otherwise impossible. 

It is presumed to be geneial'y known that Prof. Bush, since the original publication 
of ihese volumes, has embraced peculiar viev/s of Christianity, to which he is at present 
zealously devoted. This fact, however, leaves the volumes in question in all their in- 
trinsic value. They contain no traces of his present theological sentiments. The vol- 
umes are stereotyped, and the plates remain in our possession, and we can testify that 
they have received no touch of alteration or emendation from the hand of the author 
or any one else. 

The publishers feel warranted, therefore, to assure the Christian public that in these 
Notes a service has been performed for the exposition, as far as they go, of the Old Tes- 
tament wholly equal to that rendered by Mr. Barnes to the New ; and when the title- 
pages contain the significant announcement of fifth, sixth, eighth, or tenth edition, it 
will be readily inferred that the work is not now put forth in an improved and elegant 
dress as an experiment, 

51 



NEWMAN <fc IVISON'S PUBLICATIONS. 



DAY AND THOMSON'S ARITHMETICS. 



From the Principals of the Albany Public Schools. 

Within the last few years no less than ten different systems of Arithmetic have been 
itore or less used in our Schools. About two years since, in view of this evil, we ex 
aminnd several of the more prominent Arithmetics, and agreed with perfect unanimity 
upon Thomson's Series as the best adapted to the wants of the pupil, and the general 
purposes of instruction. 

We are happy to say that, after a trial of more than two years, we are confirmed as 
to the excellency of the books, that they have grown in favor by daily use, and that we 
have succeeded in making better arithmeticians than by the use of any other books. 
SAMUEL STEELE, A. T. BALDWIN, 

J. W. BULKLEY, WM. H. HUGHES, 

WM. JANES, WM. L. MARTIN, 

ROBERT TRUMBULL, TUGS. VV. VALENTINE, 

E. S. ADAMS, JOEL MARBLE. 

Albany, April 20th, 1850. 

From Hon. Judge Blackman, A.M., Chairman of the Board of School Visitors of the 
City of New Haven, Ct. 

James B. Thomson, Esq.— Dear Sir :— I have examined with attention your" Practical 
Arithmetic," and consider it decidedly the best work for inculcating and illustrating the 
principles and practice of Arithmetic which I have ever seen. Your illustrations, in the 
form of problems to be solved, are drawn, in a great measure, from the familiar scenes 
of early life ; and while the young learner is interested in the solution of problems which 
he feels are practicable, he is encouraged to persevere in a study which would other- 
wise be dull and forbidding, and is thus imperceptibly led to acquire and understand the 
rules of Arithmetic, which he now knows to be true. 

I remain, dear sir, very respectfully yours, 

ALFRED BLACKMAN. 

At a meeting of the Board of School Visitors of the First School Society of the city 
of New Haven, Ct., duly warned and convened — 

Voted, That the u Practical Arithmetic," by James B. Thomson, A.M., be prescribed 
for use in each school of this society. ALFRED BLACKMAN, Chairman. 

Certitiod by II. G. Lewis, Secretary. 

From S. S. Green, A.M., Principal of Philips , Grammar School, Boston, Mass. 

Mr. Thomson.— Dear Sir: — I hereby acknowledge the receipt of a copy of the 
"Practical Arithmetic," to which I have given sufficient attention to be convinced that 
it possesses superior merit as a text-book. I am particularly pleased with the practical 
character of it, the systematic and natural arrangement of its parts, the exactness of the 
definitions, tho clearness with which the principles are explained and illustrated, and ^ 
the concise, yet explicit language, with which the rides are stated. You havo dono a 
good service by removing from the tables of weights and measures all denominations 
out of use, and by introducing those adopted by the General Government. The work, 
in fine, is wel) adapted to the purposes of instruction. SAMUEL S. GREEN. 

From Bev. C. Pierce, A.M., Principal of West Newton State Normal School, Mass. 

To Mark H. Newman, Esq.— Dear Sir :— The copy of " Thomson's Higher Arithmetic," 
which you put into my hands, I have examined "with considerable care. Mr. T. liu 
given us, if not the best, one. of the best, school-books which have appeared in this de- 
partment. Besides happily setting forth and explaining the common principles of num- 
bers and their applications, illustrating the same by appropriate examples both abstract 
and practical, his book contains many suggestions, in regard to the nature of numbers 
tad modes of operation, which are ingenious and useful. • C. PIERCE. 

From Bev. J. D. Wickham, Princ'pal of Burr Seminary, Manchester, Vt. 

Having examined, with some care, the Practical Arithmetic, and the Higher Arithmetic 
of Day and Thomson's Mathematical Series, we know of no Arithmetical treatises that 
appear so well adapted to meet the wants of our Common Schools and Academies. 
tVith this belief, we purpose to adopt them for use hereafter iu the Burr Seminary. 

J. D. WICKHAM. 

16 



JHSWMAN & IVISON S PUBLICATIONS. 

Fr<?7re «#.e Principals of «Ae Public Schools in the City of New York. 

After a careful examination of " Thomson's Practical Arithmetic," we cheerfully ex- 
press our hearty approbation of it. Having used the work in our Schools, we are" free 
to say that we deem it better adapted to the purposes of instruction than any other text- 
book of the kind with which we are acquainted. 

WILLIAM BELDEN, Prin. No. 2. GEORGE MOORE, Prin. No. 11. 

LEONARD HAZELTLNE, « No. 14. CHARLES S. PELL, " No. S. 

A. K. VAN VLECK. " No. 16. WILLIAM H. WOOD, « No. 15. 

DAVID PATTERSON, " No. 3. ASA SMITH, " No. 12. 

WILLIAM H. REUCK, « No. 7, THOMAS P. OKIE, « No. 6. 

NATHANIEL W. STARR, " No. 10. MARVIN W. FOX, " No. 17. 

JOHN PATTERSON, " No. 4. J. A. FERGUSON, « No. 18. 

JOHN H. FANNING, " No. 13. E. G. BRUCE, " No. 9. 

M. J. O'DONNELL. « No. 5. WILLIAM W. SMITH, " No. 1. 

Saw York, Oct. 5th, 1848. 

From the Commissioners and Inspectors of the Thirteenth Ward School, JVew York. 
The undersigned, Commissioners and Inspectors of Common Schools of the Thir- 
teenth Ward, take great pleasure in stating that, after a careful and prolonged ex- 
amination into the relative merits of a great number of Arithmetics presented for their 
consideration, which number embraced all the most popular ones in present use, they 
have unanimously adopted Day and Thomson's Mental and Practical Arithmetics for 
the use of Ward School JVo. 19. recently organized and opened under their supervision 
— these books being considered, for perspicuity of arrangement and adaptation to the 
comprehension of the pupil, with or in the absence of a teacher, preferable to any books 
on the same subject which have come under their consideration. 

WILLIAM A. WALTERS, 
WM. TYLER ANDERSON, 
CHARLES D. FIELD. 

From William Belden, Jr. A. M., Principal of Ward School JVo. 3, JV. Y. 

A careful examination of Prof. Thomson's "Practical Arithmetic" has satisfied me 
that it is a work of uncommon merit. 

The plan of presenting examples, in order to introduce the rule by previously analyz- 
ing its principles, will commend itself to every experienced teacher as the natural pro- 
cess, both for imparting knowledge of this subject", and giving correct habits of mental 
discipline. The language of the explanations and rules is peculiarly clear and intel- 
ligible, and the amount and value of this part of the work much superior to that of any 
other arithmetic with which I am acquainted. WM. BELDEN, Jr. 

From Thomas Follke, Esq., Principal of Ward School JVo. 14, JVew York. 

Having examined with care Thomson's Mental. Practical, and Higher Arithmetics, I 
am pleased to have it in my power to state, as my unqualified opinion, that I consider 
each work excellent in its kind ; and, as a whole, the series is decidedly the most philo- 
sophical in its arrangement, lucid in its illustrations, and superior in its adaptation to the 
wants and purposes of the school-room, to any other with which I am acquainted. 

I shall recommend the introduction of the series into the school with which I am con- 
nected, at an early day. THOMAS FOULKE. 
We heartily concur in the above recommendation. 

WM. KENNEDY. Prin. Ward S. No. 2. 
A. B. CLARK, Prin. Ward S. No. 16. 
J. J. ANDERSON, Prin. Ward S. No. 1. 

From W. C. Kiebe, Esq., Principal of Ward School JVo. 19, JVew York. 

Having used " Thomson'3 Practical Arithmetic" during the past year, it affords ire 
ranch pleasure to commucicate my unqualified approval of it. 

It is comprehensive without unnecessary details', its rules are simple and practical, ita 
elucidations clear and explicit, and its examples combine information of great practical 
utility, approaching near the actual business transactions of life. It is indeed a treatise 
Well adapted as a text-book for our schools. W. C. IvIBBE. 

From L G. Hcbbs, A. M., Principal of Mount Washington Institute, JVew York City. 

Gentlemen: — I have carefully examined Mr. Thomson's "Practical Arithmetic," and 
do most heartily add my testimonial to those already given in its favor. It is indeed a 
work of very great merit, comprising many excellencies in a small compass. Its value 
as a practical school-book will be more apparent on a second and thorough examination. 
While as an elementary work it deserves a place in our best schools', / know of no 
tther so well adapted to general use-, ISAAG G. HUBBS. 

17 



NEWMAN & IVISON'S PUBLICATIONS. 



McELLIGOTT'S YOUNG ANALYZER; 

Being an easy outline of the course of instruction in the English language 
presented in McElligott's Analytical Manual, designed to serve th« 
double purpose of Spelling-Book and Dictionary, in the younger classei 
in Schools. By J. N. McElligott, A.M. 25 cts. 

The Youno Analyzer presents an easy outline of the course of instruction more 
fully developed in the author's larger work. It. is, therefore, specially adapted to the 
wants of the younger classes in schools ; though in cases where a more extended course 
Is denied, it may, perhaps, serve well enough for pupils of more advanced years. 

The plan of both works is of course the same. That plan is simple, yet thorough; 
offering, in the opinion of the most competent judges, the surest and shortest way to a 
due and true knowledge of English orthography and definition. For, making spelling 
a systematic exercise in writing, instead of, or rather in addition to the ordinary prac- 
tice of oral spelling, it thus takes the most natural, though, strange to say, the most 
novel method of fastening the forms of words upon the memory ; while, to fix in the 
mind their true significations, — following still the course of nature, — it compares, con- 
trasts, analyzes them, and so unfolds their real force in all their various applications. 

In respect to the mode of using the book, nothing need be said beyond the few sug 
gestions made in the course of the work. Every teacher has, and must have, his own 
particular way of imparting knowledge, whatever book he may adopt, and, in thia 
liberty he may not be disturbed. 

With the full assurance, however, that the course of study here proposed will better 
Berve the purpose of imparting a more deep and critical knowledge of our language, 
than can be acquired by the dry and repulsive methods now generally employed, this 
little introductory volume is respectfully submitted. 

It is used in nearly every school which has adopted the Analytical Manual, as an in- 
troduction to that work, and is highly approved by all teachers who have had occasion 
to give it an examination. 

We have room for the names only of the following gentlemen— all instructors of higk 
•landing— who, with many others, have examined and recommended this work. 

REV. JOHN J. OWEN, Principal of Cornelius Institute. 

REV. J. F. MESSENGER, " Classical School (B/ooklyn). 

MILTON C. TRACY, " Mech. Inst. School. 

M. J. O'DONNELL, " Public School No. 11. 

THOMAS FOULKE, " Ward School No. 1. 

WM. A. TAYLOR, (formerly) " All Saints' School. 

R. LOCKWOOD, " Classical School, Broadway. 

G. S. BROWNE, " New England Institute. 

CHARLES WM. NICHOLS, " City Institute. 

£. II. JENNY, " Classical School, East Broadway. 

AARON RAND, " Classical School, Pearl Street. 

JAMES G. RUSSELL, " Col. and Com. School (Brooklyn). 

HENRY SWORDS, " English Academy, 6lh Avenue. 

BENJ. FOWLER, * Select School, Bedford Street. 

18 



XEWMAS <fe IVISOX'S PUBLICATIONS. 



THE ANALYTICAL MANUAL, 

By James N. HcElligott, A.M, formerly Classical Principal of the Col- 
legiate School, New York city. 62^- cts s 



U e c o m m t n h a t i o n s . 

8V»#w the Hon. Theo. Frelivghuysen. formerly Chancellor of the New York University) 
and now President of Rutgers College, JVew Jersey. 

I have examined with care the " Manual of Orthography and Definition," prepared hf 
Mr. J. N. McEIligott, of this city, and take pleasure in commending it to the favorabla 
consideration of the friends of education. 

There is a fund of good sense, practical wisdom and useful arrangement in this work, 
'lot often combined within the same limits. It will, I am persuaded, greatly facilitate 
Ihe study of our language ; and teachers, as wsfi as learners, will find cause for thankful* 
teas to the meritorious author. 

JVeioForft, March 10, 1845. THEO. FEELING HTJYSEN. 



From the Superintendent of Common Schools for Ihe City and County of JVew York, 

New York, 24th February, 1845, 
J. N. McElligott, Esq* : 

Dear Sir— I have examined with much attention and high satisfaction, your " Manual 
ef Orthography and Definition," and cordially comply with your request in expressing 
my estimate of the work. Its plan has the merit of novelty, and by its simplicity and 
Eatural adaptation to the purpose of both teacher and learner, would seem to be such a 
one as would develop itself to the experience of a practical man, intent on discovering 
the best means of imparting knowledge, on this intricate and most difficult subject ; 
and yet I have never seen a work, the classification of which appeared to me at once no 
intelligible and complete. 

Within the compass of 200 pages you have condensed an amount of critical informa- 
tion upon the philosophy of the English language, which I apprehend i3 not to be found 
in any other single volume ; and your extended analysis of compound words with their 
prefixes, suffixes, and radicals, accurately discriminated ; and the synthetical recompo 
iltion of this multitudinous variety of word3 out of their elements with all their syno» 
Eymes, contrarieties, ambiguities, and arbitrary variations, must have imposed an amount 
of labor, which none but an amateur in the profession of teaching could have patiently 
endured. I cannot doubt that your reputation as a philologist will be enhanced by the 
publication of this work, and I sincerely desire that the just appreciation of your utilita- 
rian labors among the teachers of our common schools may obtain for this excellent 
manual a share of patronage, which shall adequately remunerate your toils, and at the 
same time contribute to the more thorough instruction of the pupils upon subjects which 
1 regard as lying at the foundation of all other scholastic acquirements. 
With high respect, I am yours, &c, 

D. MEREDITH REESE, 
Eupt, of Common Schools for the City and County of New York. 

19 



NEWMAN A IVISON'S PUBLICATIONS. 



SPENCER'S NEW ENGLISH GRAMMAR. 

Price 37 eta. 



TO TEACHERS, SCHOOL SUPERLVTE.VDE.XTS, be. 

The Publishers desire to call renewed attention to this New Grammar. It is aa 
original work, and not a mere compilation. It aims to teach the pupil how to me the 
English language correctly, and not how to " Parse' 1 '' what others have written or said. 
Although it has been before the public but a few months, it has received higher and 
more decided commendation from those competent to judge, than any other work on 
the same subject ever published in this country. Attention is respectfully called to the 
following Testimonials : 

From Rev. Simeon North, D.D., President of Harv. College. 

" I take pleasure in saying that the work appears to me to be characterized, in a high 
degree, by a philosophical and scholar-like spirit ; that it is marked by great clearness 
and conciseness in its statement of grammatical principles ; and that, in its statement 
and development of the whole subject, I believe it to be admirably adapted to the 
wants of students in this department of learning/' 

From Rt. Rev. Alonzo Putter, D.D. 

" It contains valuable matter not usually found in Elementary Grammars ; it states 
principles with great clearness and brevity ; it gives, to a greater extent than is com- 
mon, the reasons on which the rules are founded, and its arrangement of topics strikes 
me as just and happy." 

From Hon. Alfred Conkling. 

" Your book appears to me to furnish indubitable evidence of an acquaintance with - 
its subject at once comprehensive and minute. You have assumed the character, not 
of a rash innovator, but of a discreet reformer. I cannot but believe that you have ob- 
tained a Ann and tenable foot-hold in advance of your predecessors." 

From Rev. J. H. Jilcllvaine. 

" I do not hesitate to say, that your work upon English Grammar is (ho best I have 
ever seen. No scholar should be without it. ... I find benefit to myself every 
time I look into it." 

From Prof. S. B. Woolworih, Principal of Cortland Academy. 

"I have determined to introduce it as a text-book in this Institution. This is the 
highest commendation that I can give to any book." 

Fi om J. T. Clark, Esq., Principal of Lyons Union School. 

" It will supply a place, hitherto vacant, among the text-books essential to the stody 
of the English language." 

ZtJ 



NEWMAN & IVISON'S PUBLICATIONS. 



From D. S. Hcffron, Superintendent of Schools, Utica, JV*. Y. 

" A plainer, more thorough and scientific method of treating the subject, I do noi 
recollect ever to have seen ; indeed, 1 think your Syntax has no equal extant." 

From Prof, J. TV. Armstrong,— Oneida Conference Seminary. 

" I esteem your Grammar among the best, if not the very best, that has fallen under 
my observation." 

From J. G. K. Truair, Principal Brockport Coll. Institute. t 

"Many of its features are valuable improvements in the study of the language. The 
analysis of sentences is an admirable substitute for the old plan of ' Parsing.' " 

From Prof. Wm, Smyth, Principal of Owego Academy, 

M The change in the phraseology I like much. The remarks in relation to ' Parsing? 
are much needed by teachers." 

From E. W. Keyes, Esq., — Cortland Academy, 

«' I have examined, at leisure, Spencers English Grammar, and have become satis> 
fled that it is, in very many respects, superior to any other that I have ever seen. Its 
peculiar characteristic is, that it is an English Grammar, and not a Latin Grammar 
ef the English language,"" 

From B. Wilco?:, Esq., Principal of Wilson Coll. Institute. 

" Ten years' experience as Principal of a school of this character, convinces me that 
your mode is the only successful modo of teaching English Grammar." 

From E. S. Hawlsy, Esq., late Superintendent of Schools, Buffalo. 

"I see many things which I must consider singularly happy advancements,— im- 
provements upon any method of treating the same points, with which I have ever 
met." 

From 17. S. Bailey, Esq., Town Superintendent of Madison. 

"The system of Grammar which you have unfolded is most excellent; it must save 
at least one third of the labor now bestowed upon it." 

# From the Literary World, (by Prof. Tayler Lewis.) 

" As a good classical scholar, (a fact which satisfactorily appears in another publica- 
tion by the same author,) he has made the structure of the ancient languages, and tho 
a priori principles of general grammar, the groundwork of his investigations ; and 
from the position they give him, he is enabled to see, and to trace out clearly, not only 
what belongs to the general laws of speech, but also in what respect they have been 
modified by the peculiarities of Ang'.o-Saxon philology. . . . The work is a small 
one, but it has evidently cost much study and great pains in the arrangement, evin- 
cing, in every part, that the author is not only a good philologist, but thoroughly ac- 
quainted with practical teaching. We feel that we are safe in commending it to the 
most favorable notice of all who take an interest in this branch of education," 
24 



KEWMAX & IVISOX'S PUBLICATIONS. 



KUHNER'S ELEMENTARY GRAMMAR 

OF THE 

Bv Dr. Raphael Kxihner, Conrector of the Lyceum, Hanover. Trann- 
"lated from the German by Samuel II.. Taylor, Principal of Philipa' 
Academy, Andover, Ma3S. Sixth edition, 12mo., 355 pages. SI, 25 

The following are some of the recommendations which we have received of this 
Grammar, and it will at once be seen that they come from the most respectable sources, 
and from those well qualified to give an opinion of the merits of such a work. 

From Rev. .Moses Stuart, Professor in the Andover Theological Seminary. 

Andover, Mass., 21st Nov., 1849. 
To those who are familiar with the grammatical works of Kuhner no recommendation 
Is needed. They speak for themselves. But to those who are in a state of inquiry I 
think I may safely say, that they cannot do better than to make use of them. The School- 
Grammar of this writer, as translated and edited by Mr. S. H. Taylor, Principal of 
Philips' Academy, of thi3 place, I regard as one of the most orderly, scientific, and 
thorough books that belong to this class. It requires, indeed, more patient and coii- 
tinued labor than it is usual in our country to bestow upon the elements of the Greek 
language. But in the sequel it will amply repay the student., and greatly facilitate a rad- 
leal knowledge of the Greek idiom. I can heartily commend it to all who are begin 
ning the study of the Greek language. MOSES STUABT. 

From Rev. B. B. Edwards, Professor in Andover Theological Seminary: 

The Grammatical works of Br. Kuhner are well known and extensively used in Grea* 
Britain and the United States, as well as in Germany. His Greek grammars especially 
are characterized by a clear and methodical arrangement, by a natural unfolding of the 
principles of ihe language, by exact definitions, and by full and pertinent illustrations and 
examples. The w Elementary Grammar" of the Greek language has been received with 
much favor, and has passed through several editions. It is constructed on the samo 
general principles, and possesses the same excellencies with the larger works. In addi- 
tion to the development of the principles of the language, there are copious and well- 
Belected exercises for translation, both from Greek into English, and from English into, 
Greek, with the necessary vocabularies. In-this way the pupil learns to combine theory 
and practice, and to associate the rule with the living forms of speech. It may be added, 
that the book is well fitted, by its simple arrangement and style, for the younger mem- 
bers of our academies, and no practical difficulty is experienced in teaching them its 
principles, B. B. EDWARDS. 

Theological Seminary, Andover, Nov. 21, 1849. 

From G. W. Lane, Professor in Emory College, Oxford, Go. 

" KUhner's Elementary Greek Grammar is exactly the work I have long wished for, 
fcnd J have no hesitation in placing it far above all other Grcok grammars in the Eng- 
lish language. Wo shall use it in the Preparatory School and College." 

From M. Sturgess, Professor of Languages in Hanover College, Indiana. 

" I have used- KUhner's Elementary Greek Grammar during the past session in this 
College, and am very much pleased with it. Tho etymology is full and exact, and in 
eome respects an improvement on any other grammar I have seen. The syntax is very 
thorough and complete. The accompanying exercises for translating Greek into Eng- 
lish, and English into Greek, are very copious and satisfactory, and furnished with ex- 
cellent vocabularies. Altogether, I decidedly prefer it to any Greek First Book 1 have 
examined." 



ined." — ~\ 

34 rjj Oct., lSo^J 



-. 






« 



8 



NEWMAN & I VI SON, 
publishers and Bookselle' "l^"^ and Mail, 

SAND RS' PRIMARY SCHOOL 00? ~.^ ""J 

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« SCHOOL READER, Kjflst ; K< -.... <0 Jg 

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« " " Fourth Hook, 

Fiflli Hook, 

SPELLING BOOK, , 

ELOCUTIONARY OH ART, 1 page. , 

Day & Thomson's Series of Arithmetics and Mathematics, 

COMPRISING 
THOMSON'S ARITHMETICAL TABLES, 
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SLATE A N I ) BLACK I!' )A IW ETi KRCI&E8, 
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Official Action o? t«k STatk ScpkrI* 
Illinois.— I avail myself of this 

best adapted to geueral ur<« in utfr Common Schools. 
D. L. GRECG 

WILLSON'S SERI£S~OF SCHOOL HISTOID 

coMl'i:l>iS'- 
WILLSON'S JUVENILE AMERICAN HISTORY. Square lOroe. With 
coIore<l Maps. 
'• HISTORY OF THE EXITED STATES, for the use 

w AMERICAN HISTORY. Bojal l-2mt>. Scliool ed 

MUSICAL WORKS, 
YOUNG CHOIR, 

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MELODIST, 
TIM ICAL GEMS, 

TIIJ FLORA'S FESTIVAL, 



'IR'KCII PSALMIST, 

KITTO'S CY< I.OP.EDIA. 
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